I'm going to try... Fallout 3

Correct!

One of the Guitar Hero games? Either II or III I guess would count as first in the current gen.

Hint for game #22:

What's your best chance to defeat the king of evil, a genetically altered psychic cat, and a giant monstrous turtle all at once?

Use the puff ball.

Super Smash Bros. Melee

What part first gave it away? ;__;

Not speaking for Scoobes, but puff-ball can only really mean either Kirby or Jigglypuff.

Although i could use Marth to beat The Showdown without tricks. Giga Bowser makes for a big hitbox, and once he goes down, the others are easy enough.

23. Mario Kart Double Dash (2003)

Down from 20th, of all the Mario Kart games I felt like this one offered my favorite selection of tracks.  The two player kart mechanic added extra fun for parties and a little more strategic choices in items.  In addition the changes to the powerslide technique were welcome to at least me due to my distaste for figuring them out in Mario Kart 64 time trials.  Among the tracks I liked:  Baby Park - This one felt completely original for its small size and was quite interesting with more laps. Daisy Cruiser - running through all the different paths on, of all things, a cruise ship felt like a really creative course.  Walugi Stadium - Took all of the great parts about the Wario Stadium course and somehow turned every race into a completely crazy adventure.  DK Mountain - It had a cannon and a long windy downhill section, end of story.  The Entire Star Cup: Wario Colosseum, Dino Dino Jungle, Bowser's Castle, Rainbow Road - The courses felt complex enough that people were going to make mistakes and it really would let you figure out who was the best.  I still think that these are the best Bowser's Castle and Rainbow Road courses created to date.  The addition of more racers in grand prix was also great and I the blue shells are slightly less of an annoyance because of how fun it is to try to dodge them or at least get others caught as well.

Clue for #22:

A popular Nintendo mascot appeared as a playable character in the sequel to this game.

22. Beyond Good & Evil HD (PS3)

I missed out on BG&E when it was originally released as a 6th gen multiplatform game, but it was a game that I had always wanted to try out. I finally got that chance when it was given an HD update and released digitally last year. You play as Jade, who is working with an underground resistance movement who are attempting to uncover a massive alien conspiracy. It's left to Jade to document the evidence of the conspiracy by sneaking into restricted areas and taking photographs. It's all rounded off with a somewhat infamous final boss battle that sees the controls reversed in the final stage of the fight.

21 is a local multiplayer classic.