I got mine from newegg:
http://www.newegg.com/app/ViewProductDesc.asp?description=11-133-109&depa=1
It has a lot of room inside so it was fairly easy to hook everything up. This was the first time I had put a computer together from scratch and it went pretty smoothly except for some confusion on getting the RAID 0 drives set up correctly. I needed a faster computer for my work.
From here on out I am building my own - it was fun to put everything together - your get to get exactly what you want - and I think I saved a few $$$s
Oh hell yeah.
Alienware's too expensive.
Dell doesn't offer that much (If ya can understand the Indian salesfolks).
I haven't trusted Gateway since my little CDROM problem.
Build-yer-own is the best way to go.