I second that =P, a custom would be cool too.

I got a standard because when I was shopping for a Custom, it made me sick to my stomach the more I realized how much money I was spending.
First thing is first: You have to decide if you want a 50's rounded neck or a 60's slim taper neck. That will narrow down some choice for you right there. For example, the Studio comes with a 50's neck while the Classic comes with a 60's neck. You can choose which neck you want when it comes to a Standard; they make both. I am not sure if the Custom comes with either neck or not. It should.
It also depends on what kind of music you want to play. A Custom is good for just about any thing. A standard is good for rock and blues. The standard is the sound you are thinking of when you think of that that Les Paul sound (as far as the current production line goes). If you are going to play heavy stuff, get the Classic. It has high output ceramic pickups in it. The same pickups that are in the Explorer and they (along with the Dirty Fingers) are the hottest pickups Gibson has.
I got the standard because I wanted a very versitile sound. I am the type to get the standard then get the more specialized models later. It think I want a Classic next.