Definitely Niacin -
YouTube - Niacin - Barbarian @ The Gate , Dennis Chambers band -
YouTube - Extraction ~Proto Cosmos~ 2003 , Return to Forever has some crazy jazz fusion stuff -
YouTube - Return To Forever (w/Bill Connors) 1974 , also Weather Report -
YouTube - Palladium by Weather Report , Cherry Five (nowadays called Goblin, maybe more prog rock than jazz fusion, but hey, still great) -
YouTube - Country Grave-yard - Cherry Five
That's for now, if you want more stuff, just say, jazz fusion is THE genre for me.