I used to play bass (hopefully again...sigh) and Steve Harris made me want to pick it up (but not try to play like him...jesus, only 'arry can do that), and I admired Claypool (another singular player), Flea (especially Blood Sugar--I love his basswork there), Billy Gould (follow the kickdrum), Trevor Dunn from Bungle, Jaco (just to make me want to cry--hands down the master of finger-picking electric bass--Come on, Come over, Birdland, etc.), and I've been listening more closely to Metallica and appreciating Cliff (isn't that last solo in Orion by him? The tone, the arpeggios--I swear it's him). I can't forget Donald Duck Dunn; the Blues Brothers was another formative listening experience. Larry Graham.
OK, metal--I don't like many metal bassplayers, as I think they too often dupe the rhythm guitar, but I like Rex on Cowboys (Darrell overpowers the bass on subsequent records), yes, Geezer kicks ass, I've always liked Frankie's tone on ATL, POT, SOWN, Ellefson, yes, Trujillo on Lights! Camera! Revolution!, Testament's Greg Christian (Practice What you Preach) and punk bassists like Klaus Flouride (DK), Matt Freeman (Rancid), Tony Lombardo (Descendents), etc.
Oh yeah, we can't forget Thunderfingers himself, John Entwistle (RIP)