Ghosthack - 30 Free Basslines WAV [free]
Wav sample pack - 35 mb
We got a nice variety of different basslines here: slow, fast, growling, deep, aggressive, upfront. We created them with Xfer's Serum and used some effects on them, for example the great new mixing plugin Neutron by iZotope. We also used some presets, wavetables and LFO shapes from our "100 Bass Patches for Serum" pack as a basis for these samples, which worked very well.
All sounds are 24bit wav files, so you can easily load them into your sampler of choice and start working with them. If you use FL Studio, just drag them from your file browser into your working space.