I just got this 3rd person rail-on shooting game, and I find it addicting. The boss battles are the best.

 

I finally Managed to find this game a few days ago(used to be sold out at the few places that had it, should have got it immediately after launch instead of waiting till I was finished with Mario Galaxy 2) and having a blast with it.
Like you said, the boss fights are awesome, some of the most satisfying in a long time. Anyone with a Wii has to own this, especially if he's an arcade shooter fan.

 

Of course it's awesome. It's Sin and Punishment. You should check out the original on the N64 VC. It's great, too.

 

Oh, I finished that one before(yay for VC!) I just couldn't pick this up early due to the low stock brought by stores(they know this is a low seller)

 

Finished the game recently, final boss was too mean. Also just saw the extended ending, I did NOT need to see that, why did they have to freak me out like that?

 

Felt a need to bump this due to it's new low price of 13$ on amazon. Anyone who has a wii and didn't pick this up yet has to buy it now.
If you don't don't dare throw around the "my wii has been collecting dust because of all the kiddy games" anymore.

Amazon.com: Sin and Punishment: Star Successor: Video Games