I would have to say Musicman Stingray 5. Most consistent bass ever, has the best B string of the 3, and the sound is killer for rock and R&B which is what I play. The neck is also killer.
I love the mids of some G&Ls but the B string dept. and consistency lacks sometimes IMHO.
Fender is great, but is the most inconsistent out of the box. The sound can the old school tone to grinding rock, and can be heard on countless recordings. The 5s all feel blocky to me though.
I don't like the fact that if I bought MIA or MIM one today, I'd have to mod it. ie (badass bridge, electronics sometimes) Every newer jazz I have seen has a problem with the saddles staying in correct postion. Especially on the G string. If its a vintage or Custom Shop fender, then its usually awesome, but too overpriced IMO.