GO WEEGEE!!!
I like Luigi more. The dude needs more spotlight (by that I mean another Luigi game). And he's more funnier. From playing the only Luigi game (Luigi's Mansion, which I still play) a lot, he kinda grew on me. In every single game that has Luigi selectable, like Mario Kart, Mario Party and Super Smash Bros., I always choose him (in SSB I always choose him first). Wonder if there is a Luigi fan club here?
Mario needs to step aside a lot more. Remember Negative Zone, Luigi's Final Smash from SSBB? The trophy of it said that the Negative Zone is "a reflection of the dark side he embraced in his brother's shadow". We don't want an evil Luigi, do we? So step aside, Mario, cuz Luigi is the star of the next Mario game (he should be... he deserves it.)!
Plus: Anyone who played Luigi's Mansion, remember the room with the telescope? If you examined it, it said Luigi wanted to visit space some day. But guess what? Mario beat him to it (Super Mario Galaxy). :(
Luigi FTW. :D