Among some fairly longish games, I've played MP3, Okami, Zelda TP, Super Paper Mario, Z&W, SMG among many other mentionables.

I don't want something that's the same thing over and over but addictingly good (Eg. Boom Blox)

Assuming that I would have to buy a game like NOW (and not wait for some obviously brilliant titles on the horizon), what would you all recommend?

Bare with me if the games you call out I have played already and didn't mention, I will edit the post when necessary!

Thanks!

EDIT: I've also played alot of SSBB, MK, RE4

Current best bets: Fire Emblem, de Blob, nIGHTS, Battalion Wars 2

Id say RE4 is missing on your list, No More Heroes... brain is off.. thinking.. will update with more when brain wakes up.

Fire Emblem. You'll spend 40+ hours on some tough game play. Then you can play it again on hard for even more of a challenge.

Go with Fire Emblem, No More Heroes, RE4 or RE:UC. =]

Dunno if you've got them already as you did not mentioned them in your post and you also have no games listed in your profile but you should seriously consider MK and SSBB. You can play each 100+ hours and still enjoy them as much as you do in the first hour.

I also vote for RE4.

RE:4 is a very good game, and has alot of replayability/extra features
Brawl and MK Are also good for racking up hours

Damn, others have beaten me to those recommendations

Geometry Wars: Galaxies
Blastworks: Build, Trade and Destroy/Blastworks: Build, Fuse and Destroy depending on your region

Go with this!

I'd say go with Brawl, especially if you have a buddy or 2, or 3, to play with. I can guarantee you will be playing that game until the next iteration comes out, if you like it . Same with MK (I personally like Brawl more).

De Blob, Battalion Wars II

Scarface, The Gothfather, Bully, No More Heros, RE4, RE:UC, Medal of Honor Heros 2, Fire Emblem, Chocobo's Dungeon, Sonic and the Secret Rings, Super Smash Brothers Brawl, de Blob, Lego Star Wars, Lego Indiana Jones, Lego Batman, Trauma Center: Second Opinion, Trauma Center: New Blood, Sam&Max Season 1, Battalion Wars 2, Naruto: Clash of the Ninja Revolution, Tomb Raider: Anniversary, Star Wars: TFU, Crash of the Titans, Death Jr. Root of Evil.

Those are all games that have at least a 70% rating in gamerankings that are somehow lengthy. There's some more but I personally wouldn't recommend.