It depends on your budget:
If you have $150 or so:
For an "active" one (meaning, runs on batteries or phantom power from the mixer)
Countryman Type 85:
http://www.zzounds.com/a--2676837/item--CTYTYPE85
For a cheaper active DI:
Stewart ADB-1:
http://www.sweetwater.com/store/detail/ADB1/
For a good passive one:
Radial JDI
This one is actually hard to buy online for some reason. You can check out
www.musictoyz.com, and see email them if they have any stock, it runs about $170 there.
Or, you can call Coast Recording:
http://www.coastrecording.com/
I got mine for $144 there (I think). Its supposed to be one of the best passive DIs in this price range (and uses a Jensen transformer as indicated), their active model is about $200 more though)
Friendly people there....
Lots of bass players in other forums, recommend this: (I'm a bass player myself, but it wasn't for me, so YMMV).
Tech21 Bass Driver DI
http://www.zzounds.com/a--2676837/item--TCHBSDR
Oh yeah, some people have used the Behringer one too. I own the Stewart and Radial JDI and have used them...
And if you're wondering about the whole passive/active DI thing, there's really no set rule. Some people might say if you have preamps on your instruments, to use passive, and vice versa...
Good luck!