ummm, that would hafta be luigi, not cuz hes the under dog, its just, i think hes cooler than mario. mario is second on my list though. see, look, list!
LIST
1: Luigi
1.5: Mario
2:Giga Bowser
3. Knuckles the echidna (i know hes not mario related, but you gotta admit, he is one of the COOLEST!!!)