Dark sonic has not appeared in the series yet
They call it Super Mario Bros Wii for a reason
No, the reason why is New super Mario bros is made my Nintendo(Mario makers) not SEGA(sonic makers)
No, but the Mega Mushroom does appear in New Super Mario Bros.
If you are referring to Super Smash Bros Brawl, then Sonic could KO Mario in a fight, sure.
If you are talking about Sonic and Mario in a Smash Bros game the they are both in Super Smash Bros.Brawl.
Super smash bros
It depends on what you want. If you want an old-school type platformer get New Super Mario Bros, if you want a sports game get Mario and Sonic at the Olympic Games. Personally, I prefer New Super Mario Bros, I feel it has better controls and is more fun. also Mario and sonic at the olympic games does not have as much activities and no story mode
If you mean S.S.B.B. (super smash bros brawl) then yes.
yes in super smash bros. and other games.
Both Sonic and Mario have appeared in Mario and Sonic at the Olympic Games and Super Smash Bros. Brawl.Some people have hacked other games to make Mario look like Sonic.
Mario Bros. Super Mario Bros. Super Mario Bros. 2 Super Mario Bros. 3 Super Mario World Super Mario Land Super Mario World 2 Super Mario Land 2 Super Mario 64 Super Mario Sunshine New Super Mario Bros. Super Mario Galaxy New Super Mario Bros. Wii Super Mario Galaxy 2
Sonic boom because it is more Famous.