
Hey,
Yea what kind of bass do you want ?
I can suggest you the novation bass Station for 303 sounding bass, it does subtractive synthesis, plus it has an external input. Also the Super Bass Station is nice, for lower bass, it has an sub Oscillator.
Moog Prodigy is a nice warm sounding synth with 2 oscillators...for that classic Moog sound, also a subtractive synth. It sounds very nice.. and it's affordable
All of the above are Monosynth meaning you can only play 1 note at a time, but you can of course multitrack them....
The Roland SH101 is also comparable to the Bass Stations and 303 and sounds very nice.
Also check out the Juno range... Juno 60, Juno 106 they are nice too, the 60 sounds a bit more agressive and doesn't have MIDI in Out ... but is very punchy ..
Mo Phatt and Planet Phatt sound to me a bit outdated..... (my opinion) And they are ROM based modules ; they use samples which are stored in the ROM... Especially Planet Phatt is aimed at the hip hop market so most sounds in there are the common uses sounds in 80's and 90's hip hop... this could be a good and bad thing, depending on your needs.
These are some of the synths I used and are nice sounding and affordable : 200 - 500 euro second hand ...
Hope that helps... but let us know what you're looking for, maybe link us to some music for examples...