Depends what sound you want.
I suggest Seymour Duncan. I got SJM-1s and Antiquity II's that I've had experience with. I like both. Antiquity pups try to replicate the sound of a vintage Jazzmaster pickup from the 60s, by slightly demagnetizing them, going as far as adding dust to them, etc, etc, etc. I'm not sure if they're a good replication as I've not played a vintage Jazzy or Jag, but they sound amazing. Also, I don't think J Mascis would purchase them if they weren't capable of sounding vintage, as he actually has money to throw around for an actual vintage pickup. Fran would recommend the SJM-2's or 3's, which I imagine are also very good. They have more of a hot sound iirc. Or you could try Jason Lollar. I've not heard any of these pups, but I'm sure they're decent/of quality/better?? than what I would expect from Seymour Duncan.