patar4097 : I agree with you on World 9-8. I think that the massive Bullet bills aren't Banzai Bills though. They're smaller than those giants.

I would agree on 8-7, but 9-8 was cool, too.  I love the track! It's so fun!

Bowser's Castle on World 8. It is pretty cool that Bowser turns giant. I also have a big gaming history for this game and I used to play it every day. I sometimes invite friends to challenge me, and if they beat me, they get a $10 iTunes gift card. So, anyways Bowser's Castle on World 8 is just amazing. It is one of the greatest levels and challenges I have ever seen in my whole life. At first I didn't beat the level, but after a whole year, I beat it at my friend's house on HIS WII! I wanted to do it on my Wii, but I did not pull it off after a week. Now, I am very skilled with this level and can pull it off 40% of the time. Sadly, I lost the game, so I bought another one, Then disappeared again. So, I will almost never forget this level. I might buy another game sometime, but I probably won't buy it until Mario Kart Wii U comes out or later! Anyways. This is pretty much the end of this post. I did not realize this post was really this long! 

I love BC on W8.

I agree with black bot. My favorite level is the last level in world 8. The level is actually pretty challenging and the final boss is really fun. That level might be one of my all time favorite mario levels. Also most of the levels in world 9 are fun.

I'd say the last level in world 9. 9-8 is just so fun, and getting through it is a challenge for some, but its so cool.

The last level of the gosh darn game i was glad when i finished it.

bossrunner : I haven't played this one but I have seen the one for the WiiU, that is pretty cool and pretty fun

My favorite New Super Mario Bros . Wii Level is 8-7 which is unlocked by a secret goal in 8-2. If you beat this level, you can skip 4 long levels in World 8.

My favorite level has got to be the final bowser battle. The first time I played it, I remember thinking I beat the game, and then he pops out of the lava all gigantic, it was awesome! No other level compared to that level.

I'm torn between two: the one in world 8, with the skeletal roller coaster thing. I can't remember the level number. It was a secret one, I think. And the Castle of World 4(the coastal world). Its platforms and blocks made the level more fun for me, and the Koopaling at the end of the castle, Wendy, was challenging for me because I hate anything to do with water in any Mario game. I didn't really like the castle in World 8, though. It was too easy with a propeller suit(I'm a coward, I know).