Buy computer or build own?

Mod: Not sure where this should go, so if it needs to be moved, move please.

I'm going to buy a new computer at the beginning of the year. My question is..Should I just buy one from Dell.com or should I build my own. There is no way in hell I can build it myself, but my neighbor runs a computer store and he builds them all the time for people. I've taken my computers to him numerous times to get fixed and he always has them ready in 24/48 hours.

I don't do anything crazy on my computer. Just the normal web browsing. Probably the most taxing thing I do on it is download music, but not like I did a few years ago when I was still in school. Obviously I would like to have good amount of memory, and be able to play poker with no hiccups. Also, I have 2 monitors, so I would need an extra video card.

So, you computer experts, what do you suggest?