Hey Rimshot,
There are quite a few ways to do this. To me, it depends on the bass as well as the player and the style of music. My bassist in my original band uses a Kubikki Factor, so we use a different front end for him. Drawmer 1968 MKII...sometimes a pre-amp or channel strip type deal. We just picked up a Manley TNT that's pretty incredible. One side is tube the other side solid state for the best of both worlds. So that's our GOOD front end for him or anyone else that can really play the bass.
Now here's the kicker....other times, as well as for myself, I get incredible results using a regular old charcoal colored, kidney bean Bass POD and I love it. It's fantastic for that "now" bass sound as well as just about anything else. It is seriously the best $299 I have ever spent and I definitely recommend it for anyone struggling with bass tones. You should be able to dial something in on that in about 5-10 minutes tops. God knows what improvements they've made to it now. I got mine about 7 years ago so it's old and outdated but man, it gets any tone I ever needed. It's not quite as elaborate sounding as the other rigs I mentioned, but it shouldn't be when you weigh the prices. LOL! See, if you have a guy that is a real bassist that has touch and feel on the instrument as well as a really nice bass that is set up right, new strings etc, you want to run him through the best stuff in your studio.
If you are working with a guy that is a middle of the road player that's a bit sloppy or is more of a "now" type bassist that likes a little drive in his tone and some sub low end...or maybe that 60's or 70's sound, the POD is fantastic for that. Don't get me wrong, if you plug a really nice bass into it with a guy that can really play, it sounds fantastic. But it's not quite the Drawmer or the Manley. LOL! :) Check it out sometime if you get a chance. If you've heard any of my productions, I just about always use the POD. Anything I put out with my band though has Joey or Wayne on bass so we use different high end gear for those guys because...well, they can play bass and I'm a hack. LOL! :) Good luck man.
-Danny