First and foremost, before deciding what model you want to buy, I would suggest going to a range that rents guns and trying them out first. No sense investing $600-$800 in a gun that doesn't fit right/feel right in your hand.
When I bought my first handgun, I went to a gun shop that had a range and rented a Glock, a S&W, a couple others that I liked the look of... after the 2nd gun at $10 each, the guy stopped charging me the rental fee because he knew I was looking to buy something. Sure enough, the 5th or 6th gun I tried was a Sig Sauer P220 .45 cal. It felt right in my grip, it felt great when I shot it... so I went to their used gun section and sure enough they had one in their two-tone finish with Hogue grips. I'm as pleased with that gun today as I was the day I bought it.
I wasn't a big fan of the 9mm back when the military dropped the 1911A1 .45 cal in favor of it due to less stopping power. I just like the feeling that if I ever need to use it, the person I use it on is getting put on their backside and not continuing toward me. But I know there are a ton of people who can provide proof that the 9mm was plenty to put them on their backside.
My next purchase, possibly either a Walther PPK or something from H&K. Sadly the days of the assault rifle are long gone.