The ones I keep returning to are:

Oliver Lieb Samples - loads and loads of stuff, well worth £60. Drums, fx, pads, basses, you name it, it's got it. And top sound quality too.

Distoteque - Lots of very grimy loops, makes you feel most unclean.

But there's nothing better than sampling offa vinyl, looping it and running through a filter for some distortion.