Big Willie Style is kind of a slap happy album. Probably the most commercial album Will has made, but it still has some tracks to put you in a good mood on it. They may not be lyrically deep or meaningful, but it's definately not a bad album.
Willenium on the other hand goes back a little bit to Code Red days...and I love Code Red. I was happy to see Jazz on some tracks on Willenium. However, you have to admit Willenium had it's Big Wille Style moments (ex:"Freakin It"). Tracks like "So Fresh" and "Potnas" definately made up for that though. The lyrics on Willenium were 5x better than BWS.
I like both albums...if I'm in the car w/ friends and want to sing-along, I'll pop in BWS. If I'm in the car and doing whatever, I might just pop in Willenium.