Whats your budget? Weight preference? Max length? What power level? I am a fan of short guns and is all I own now for a couple years. My personal favorite is the Evol Mini. Such a top notch gun. While I personally haven't owned one if I were to do all out bullpup I'd go with the Ghost. I'd be torn on the Carbine or Plus version though. But both are expensive.
Cheaper I'd say Taipan Vet1 Short, Uragan compact, RTI Prophet Compact are all great and personally owned. Others I haven't owned are the various BRK carbines, Lelya 2.0, Caiman/X, and Krait with the new regs are all great guns. I'm no FX fan due to there barrel systems and lack of true stability that many have spoken out about but people do like the Dreamline compacts. The Panthera Hunter compacts seem nice and better barrel lockup. I think this is your middle of the road Budget guns probably from $1000-$1700.
Then cheap I'd recommend the Notos. Such a great gun for the price. People still like the Prod but for what it is it's severely lacking compared to the Notos. I've owned a few in the past and you could throw alot of money at them but personally think the Notos is the better gun unless you just want a project gun to build up.
Doesn't hurt to look for used from a well known member. That's what I do before I ever buy a new one. I own a Evol Mini .22, Uragan Compact .22 and a Notos. All were used except the Notos.