UI SOUND EFFECTS and ALLIEN ATMOSPHERES seem to be my most popular and best selling SFX libraries so far. MINI UI (a lighter FREE version of UI SOUND EFFECTS) has been downloaded nearly 1k times. Thanks guys!
At the moment I'm working on few more SFX libraries. Probably the most interesting (and time consuming) project I'm working on now is mix of organic and modular synthesized sounds morphed together. This one takes a lot of time to develop so it'll probably be out in ~2month. More libraries (including FREE ones) to be added soon.