Jason, you have just asked the most epic troll question ever in the firearms community almost like saying on a fitness board I am trying to decide to do Crossfit or Westside.
People would be screaming at each other for weeks about this one.
Here are a couple of points. The Glock is a super weapon. You really can't go wrong with it. There is one really important consideration. The safety is integrated into the trigger. This isn't necessarily a bad thing except in one situation. I am now explaining it as the Plaxico Problem. If you drop a weapon the very first instinct is to try and catch it. With a Glock this is problematic because as you grab it there is a real possibility that you could accidentally grab the trigger and discharge the weapon. This alone shouldn't stop you from getting a Glock but I really recommend you understand this.
Both the Sig and the Kimber that Kevin recommended are phenomenal weapons. My personal favorite is the XD or XD/M series from Springfield. They incorporate the trigger safety of the Glock plus the backstrap safety of a 1911. This provides an additional layer should you drop the weapon while still giving you the ability to carry the weapon in condition 1. Two other things I like about the XD/M series is that it will shoot any ammo you run through it, second is that it has a tactile chambered round and cocked hammer indicator. You can by touch with your weak hand tell if there is a round in the chamber and if the weapon is cocked.
The caliber debate is never ending. The most important considerations to me is that you have a weapon when needed, the gun fits your hand size and that you can put lead on target. A .45 that you don't carry or flinch when you fire is absolutely of no value for personal protection. I have personally always preferred the .40 but have standardized with the 9mm as my wife is very comfortable with that round and it didn't make since to have multiple weapons in different calibers.
I will say on the caliber debate that I would avoid the .380 just because the price of ammo is so ridiculously stupid for that caliber it isn't worth it.
The best recommendation I could make is to spend some time shooting multiple weapons in different calibers. I can dig up a ton of link on these subjects if you are interested.