So i've been doing my research on handguns and have come to the conclusion I want a 9mm in a full size or slightly compact model depending on the gun.  Being 18 I can't conceal it so size really isn't a factor.  I'm looking for reliability as well as a good investment for the money being spent.  So far i've been set on getting a Glock 19, but have begun to look at some others.  This will probably be the only handgun I get before I turn 21 so it will have to be a jack of all trades.  

Overall I think the debate comes down to Glock 19 vs CZ 75 vs 92fs, (or maybe a px4 storm, haven not looked into those much though).  Open to suggestions and thoughts about other possibilities.  Not interested in M&P models, heard too many negative things about them.  Just for context I prefer the 19 over the 17 because my hands aren't the biggest so it feels better.  

Any advice or opinions would be appreciated!  Thanks in advance!

19 would be a great choice!

I like the 19

Can you own a handgun in your state under the age of 21?

19 or a p07

Glock 19 gets my vote.  CZ would be second recommendation.... and the Beretta well let me just say I have a bias toward them and if you wanted a alloy frame I would recommend a Sig P229 over a Beretta.

Hhmm.  My first reaction was to suggest the M&P.  I own several and love them.  I'd be interested to hear all the negative you've heard?

Any how, I'm not a Glock fan so I'd suggest the Walther PPQ or maybe a SIG P320 for striker guns, or the CZ P07 or Beretta Vertec for SA/DA

All the cool kids have Walther P99s.  

Seriously, pick a P99 up in your hand and heft it and you'll never feel the same way about a Glock.  Accurate, reliable, highly recommended.  

Glock 19 would be my choice.

Jack of all trades you say? 2.25 inch sp101. Way more utility than a glock 19 and it'll be passed down to your kids.

Gotta go with the G19.  It will invariably fill the vast majority of roles you want it too.  Small enough to conceal, yet big enough to shoot well, great mag capacity, it just fits into that sweet spot as a daily carry piece, fun gun at the range, etc.

Or, since you can't conceal, this would be a great time to get a nice full size gun like a ruger 357 or even a 1911? No reason to go small if you don't have to.

Edit: I see you want a 9mm. Glock 19 is an excellent choice but you could always go larger since conceal ability isn't an issue. Glock 34 would be a fun first pistol! A good target gun too.

Glock 19 all the way, I have had 9mm's in Sig, Beretta, CZ and Springfield and only have Glock 19's now. 45's are a different story though.

Get a CZ75 compact.

Glock 19 all the way! Cz75 second. The Beretta comes in very very last. I shoot the beretta for my military quals and daily carry and while i shoot expert every time with it i think it is one of the worst handguns ever. The glock 19 will make a great carry gun and you can compete with it as well. I do both and have actually won several idpa events with my 19

Ahhhhh, this is too hard.  Only 1 gun?  There are too many good ones.  I bought a G19 for my first pistol only to sell it less than a year later.  It is NOT for everyone.  I personally love the Walther PPQ and the CZ 75 series, but I don't know if I could decide between the two.

I won't tell you what pistol you should buy because you haven't provided enough information yet.

You've said carrying isn't a consideration. But the 3 pistols you listed are fairly different. You should start by determining what type of action you prefer. Do you want a striker fired pistol, where every shot will have the same trigger pull, a DA/SA where you have to master both pulls and the transition, or a SA where you have to master the safety manipulation? Or DAO if that's your thing.

Once you've made the decision about the action, it will guide you to your next decisions. ETA: what is the budget for the purchase?  Do you want polymer framed or metal? Polymer is lighter, but metal will tend to absorb and reduce felt recoil.  Do you want a safety, whether passive (grip) or manual (lever)? What about ergonomics?  Do you want ambi controls?  What type of mag release works best for you?  How do you naturally point?  

Once you've answered these questions, it will narrow down your selection. Normally I'd say rent the ones that match your criteria and buy the one you shoot the best. The pistol that feels the best in your hand night not be the one you shoot the best. But if you're 18, that's not likely to be possible. It also means that you're limited to willing private sales, which will also narrow your options.

Finally, make sure to leave yourself some extra cash for a training class from a reputable instructor.

Good luck!

The M&P is an excellent handgun, you would be missing out on one of best guns out there.  The Glocks are great guns, the Walther P99/all other Walther's, Beretta 92's/Storm are also great choices.

G19-26. CZ75B, Walther PPQ, M&P9C, Sig 226-228, all great guns from first hand experience.

This.

I have three of the things and I well never, ever go back to a Glock.

Shoot all of your potential choices before you buy if you can. You'll be glad you did before laying down cash for a pistol that may not be something you really like.