Gen 5 if that's what the 19X is.
Had a Gen 3 and didn't really care for it. Shot the Gen 4 the best but the 19X is just behind it.

I voted for the Gen 4, because I took the poll question too literally, but I really, really like my G19X.

When (not if) I buy another G19 variant, I will probably go Gen 5 just to have both versions. I'm not going to try to collect all the versions. That's if I don't buy a G45.

I also have a G23 in Gen 3 that I really like a lot. (I know, not relevant to this topic...)

I carried a Gen 2 for years, but as noted, the inability to easily mount a light and the lack of grip texture were drawbacks. I skipped the standard Gen 3 in favor of an RTF2, which I eventually let walk after deciding I liked the Gen 4 better. Heresy, I know.

I used to hate the finger bumps on the front strap, but anymore, they don’t bother me. They don’t seem as pronounced on the Gen 4. What I really hate is the half moon cutout on the front strap of various years of production. Thankfully, my Gen 4 doesn’t have it. I don’t see a personal need to get a Gen 5 at this point, even if they get rid of that stupid cutout, the Gen 4 does what I need it to do.

That said, I’m fairly tempted to pick up a G45.

I've owned a couple Gen2's, a couple Gen3's, and now a Gen5.

I prefer the Gen5. Cosmetically, the lack of finger grooves and beveled slide edges are nice, but what really gets me is the grip texture and grip shape which to me is truly the first time Glock has got it completely right straight out of the box.

Functionally, I like the flared mag well, the double captive recoil spring, and the new trigger system which feels quite good right out of the box and doesn't have the trigger return spring which can be a point of failure.

The one critique I have is that I do not care for the half-moon cutout at the bottom of the frontstrap (this was revived from the Gen2). I could do without that, but it sounds like some variations like the MOS do not have it.

I've had a Gen 3 for many years, feeds and shoots everything reliably and accurately. Have Milt Sparks and Bulman leather for OWB carry. The Gen 3 is a great pistol, my fave 9mm of all time. As it was called years ago, Combat Perfection. It truly is!

I used to have a Gen3 Glock 23, so I voted Gen3 Glock 19, though honestly it'd probably be a toss-up between the Gen3 and Gen4 Glock 19 for me. While I'm not a fan of finger grooves, in general, the mid-size Glock's grooves fit my hand better than other finger-grooved guns I've tried; never had a problem with them. The full-size Glocks, not so much.

While I like that the Gen5 Glock 19 has no finger grooves, the notch at the bottom of the front strap started bugging me before I was halfway through a box of ammo.

More importantly, though, is that I can't run my favorite trigger combo, NY1/"-", with the Gen5 guns.

So, yeah...if I were to get a Glock 19, it'd probably be a Gen3, but a Gen4 would be a viable option if I couldn't find a Gen3.

I didn’t get into glocks until Gen4. .
The Gen 3 glocks felt too slick to me. The gen4, to me, has just enough rough to it for a good grip.
The gen 5 glocks just don’t do enough extra for me (but I do have one Gen5 G19). The finger grooves were never a big deal to me.
The biggest improvement on the Gen4, IMO, was with the large frame pistols (G20, G21, etc. ). The standardization to the SF frame measurements WAS a big deal to me.

First one I had was a Gen 2 G19 that I traded into. It was pretty slick and gave me Glock knuckle under the trigger guard. Eventually sold it off and stuck with HKs for the time being.

Gen 4s sold me on the pistol and is what I have to carry these days, but after getting a G45, I see the Gen 5s are a bit better - well at least when they get rid of the stupid frame cutout.

Eventually I'll get a Gen 5 or two, but it's not a must have with my vetted and proven Gen4s.

Have two Glocks currently:
G4 19.
G3 20SF
And I just sold a G3 23.

I have owned a gen 2 years ago but got slide bite and sold it. Years later I bought a gen 3 thinking maybe the finger grooves will help offset my grip. Didn't happen but the wife liked so it was hers. I now have a gen 4 and love it.I just wish Glock would make the tang a little bigger so you don't need the additional beaver tail pieces for guys with big mitts.

I have Gen 3 and Gen 4; either are fine.

I carry the same size frame in the G32 (.357 Sig) in both Gen 3 and 4, but most often the Gen 3. I don't know that it makes much difference.

I voted for gen 5. I own one of each (2, 3, 4, and 5). I found the stupid cutout to be uncomfortable and added an SLR Rifleworks mag well to cover it. I think the gen 5 trigger and finish are nice improvements.

Having all but the gen1 of course, the gen4 is by far my favourite.
I'd like the gen5 better if it weren't for the ambi slide release.

I have 3 (not counting the 19x). Two are gen 5, one is gen 4. I choose the gen 5 because of the trigger out of the box. I run my Glocks stock except for sights and a factory extended mag release, and the stock gen 5 trigger is wonderful. Even better on the more recent production pistols.

The only one I've owned and shot is a Gen 3.
Great gun. reasonably accurate for me and flawless from a functional standpoint.
I have a hard time getting excited about shooting it so I don't, very much. It stays locked up with a few others I don't shoot much.

Gen4, but I don't have any vast experience with Glocks.

Shot a Gen3 years ago (before Gen4's appeared). Didn't like the texture and the grip was too big for me.

Bought a Gen4 G34 (2011) and a Gen4 G19 (2013). Not because I was a Glock fan. First, arthritis was slowly creeping into the fingers. I wanted to prepare for the day when I might have problems shooting my DA/SA Sigs and 1911's. Second, the backstraps and/or GFA would allow me to fit the grip to my requirements.

G34 shot fine, G19 didn't. Recently determined it was the damn finger grooves on the G19. Didn't shoot either much until this year. Removed the G19 finger grooves. BAM - problem solved! Installed Defoor black/black sights and installed smooth GFA over M backstrap...perfect fit. Ready to write a book now titled "How I learned to love my Glock" Now one of my primary carry guns. Decided to buy a second G19 for fondling/dry-firebackup.

Since the finger grooves were my problem, I considered a Gen5 G19. Spent a lot of time researching and at the LGS. Wasn't looking forward to removing the bumps a second time, but decided to go with the Gen4.

Why I didn't go Gen5:

1) Frontstrap cutout. Wasn't going to spend good money on a new pistol and find out it chewed my pinky up after 50 rounds. Also possibility of snagging front of mag on cutout during sloppy reload. Dumb feature.

2) Magwell flare. I have X-Grip adapters. Not for the extra two rounds, but because I like the grip feel. Still undecided, but can't use them with the Gen5. One less option.

3) Ambi SSL's. No need and may require different holster than Gen4. Also possibility of catching during re-holstering, especially with a Vickers ambi. My other G19 has a Vickers SSL because my old thumb can't actuate the OEM version reliably.

4) I have heard reports about the Gen4 barrel throat being shorter than the non-Marksman barrells. I shoot a lot of hard-cast lead reloads. Didn't want to gamble on having to change my specs for one 9mm. Doesn't matter whether this is BS or not. One more potential gamble.

5) Front slide serrations. Not a deal breaker, but I hate them. Saw a guy nearly blow his finger off using the front serrations on a 1911 during a malfunction clearance. No, he wasn't an inexperienced bozo. He was an experienced, safe, responsible shooter. S--t happens.

6) The trigger on my first Gen G19 was just fine. So was the second. Couldn't see much difference between those and the Gen5's I handled at the LGS.

Now I have two identical Gen4 G19's and am a happy camper. They do everything I could ask of a defensive handgun.

I have 2 gen 3s. Out of their box, I never liked the grip or the trigger. Their accuracy was not as with CZs or Sigs. I dremmeld the grips, the trigger guard, changed springs, triggerhousing, trigger and barrel. I also felt the same for the gen 4, so all innards are non Glock. Not so with my two gen 5s G19! Triggers and barrels are great! Barrels and accuracy makes me a true believer...except for the moon shaped cut at the bottom of the grip. That’s why I have two. The second one has the half moon cut solved. It is the G19 mos. the half moon issue on the other one I solved with a Zev mag well.
Congratulations Glock!

Gen 4 were great, but gen 5 is better.

Gen 4. I like the finger grooves. I do like the Gen 3 RTF2 also, but it's a little too aggressive for carry, and I prefer the smaller circumference of the Gen 4 grip.

I have Gen 3 and a Gen 5. I like them both.