I think, and I'm sure others will agree, that the type of firearm you are looking for is directly dependent on what you intend to use it for. They are a tool, not a toy, and not a fashion accessory - despite looking really dang cool. lol
Is it for protection? For target? For hunting? I'm assuming you're going for a handgun here, too - revolver or pistol? Do you want something that you can handle easily, or something to really pack a punch? If you are going to be using it for target, does the price of ammo cause any concern? Also, when looking at the frame size itself, consider the "fit" of a gun to your hand. I have big hands, and anything smaller than a large sized frame doesn't quite work for me.
For me, my ideal first gun was what I went with:
Taurus PT-99 (9mm)
9mm, adjustable rear sites. Replaced the stock grips with Hogue rubber and that's it. I've shot a few thousand rounds out of it and never had any problems. It has an internal locking mechanism with a special key - something important to me because at the time I planned to have kids, and now I have a 2 yr old daughter. Some call it a "Beretta Knock-off", but like I said, no problems with it. It's ergonomic and does the job. Bought it during the Clinton era so it came with a 10rd clip. Bought an aftermarket 15rd one for it, too. I've done a timed "fire for your life" run, all rounds + mag change, in about 4 seconds. Sure, I may not have hit anything, but I'm sure that if you have 25 rds coming at you that fast, any adversary isn't going to have dry pants for very long.
Why 9mm? Why not larger? A well-placed shot counts, no matter what caliber. If you take the time to learn to shoot it well, and in different situations (eg, advancing on a target, backing away in defense, etc), you don't necessarily need to be blowin huge holes. Also, in defense of the 9mm, ammo is a lot less pricey than that of a 40 or 45. If you want a bigger hole, buy a better bullet.
Price when I bought it: $450