I looked and only found one review for Mario Party 8. It gave the game an 8.3 which was really mainly because there wasn't a story line to it, like most mario games.
Let me detail some of the better games for you.
Project HAMMER - Not much is known about the game, but apparantly robots have taken over the city so you have a giant hammer and you smash them with it. It's supposed to have some good physics to it or something. Like I said not much is known, but it's a second party game so it's bound to be good.
http://www.youtube.com/watch?v=79zWv3xbcxY
No More Heroes - An artsy and very violent assassination game. Apparantly they have said that they are aiming for a level of graphic violence comparable to Manhunt 2. When you become the 11th greatest assassin you are entered into some kind of a competition to kill the other 10 that are ahead of you. A lot of what I have seen seems to be rather early on in the development stage so far. At least I hope because those voice overs sucked. This one I am really mixed on. Could very easily be another Red Steel, but they are taking their time with production on this one so who knows.
http://www.youtube.com/watch?v=HGtgqw3IsVI
http://www.youtube.com/watch?v=tDSot5r1TzM
It sounds like they realize the voices were too clear and audible in the GDC one so they toned em down there.
Battalion Wars 2 - An interesting take on the RTS game. Unlike C&C these people realize that the regular PC interface is an abomination on a console control sytem. You get to take control of individual soldiers, and command the other troops by either taking them over or calling out an order to them. (not sure how that works though).
http://www.youtube.com/watch?v=MaUd0s0veUg
Disaster: Day of Crisis - you are some sort of anti terrorist specialist and a group of terrorists have taken advantage of a series of natural disasters in order to take control of a nuke. I don't know much else about the game. I assume it's an FPS though. (third person actually, after watching the trailer)
http://www.youtube.com/watch?v=BHaItCFGI_g
Resident Evil: Umbrella Chronicles - Mansion setting, zombie game, Third Person Shooter (most likely), possible remake of the original. I think we all know what to expect from it, but with Wii controls.
http://www.youtube.com/watch?v=WLtfGZWDBcI
I am gonna skip the other popular ones like Metroid or Final Fantasy, I think we all know what those are about. As for ones like Tamagotchi... they don't look too promising so I am not gonna take up your time with them.