I find with basslines its almost as important to work on your mix than the bassline itself.
Need to think about what your track is doing, and what sort of bassline you are going for because its going to affect every other element of the track.
If the bassline is the main feature you have to build everything else round it.
If its supposed to help drive along the groove, you should incorporate it after you've got your groove.
You'd be suprised how ordinary the actual bassline sound itself is on many outstanding tracks. Its more down to clever positioning in the mix.
Listen to D&B for some ideas on how to use bass. The tracks with the biggest basslines just have percussions sizzling on the top, and the bass takes up nearly all the space. Other tracks are more percussion led and theres just a deep sub adding depth.
Really depends on what you are looking for. Give us some examples mate, sure we can help ;)