Ooh! This is gonna be a long list! I love em all.
650 Indy's? On the hard pack my 83 V-Max 540 handled those with ease. The 1st gen V-maxs gotta be on there, never mind world champion status!! Speaking of which, the early SR's were the original giant killers that set the stage for the 77 SRX's butt kicking antics, so they gotta be on there too.
Exciter SX, hell yeah! No contest, my brother in law had a 650 Indy RXL, I'd ride the Exciter any day over the Polarass.
V-Max-4, check! 77 SRX, check! SRX 700, check! (My 98 SRX Mountain runs circles around a stock 98 MXZ! I know, I did it!)
The other guys may have played in the triple/triple field for awhile before Yamaha, but Yamaha showed everyone how it was done!
Early Exciters, check! GPX's, check! GP 440, check, (unbelievably like a moose in the snow!) Phazers, (a MUST!) check! Not to mention the incredible, current offerings! Need I go on?
Yamaha baby!