I think the best are made by KWA as part of their PTP range, KSC because I >think< they're just KWA rebranded, or as good as being rebranded and obviously the TM if you don't mind your pistols being plastic.
I know that KSC are good for realism, they often have the proper trades and are of a more realistic weight. KWA have airsoft related trades, which I consider a bit of a turn off and TM are just TM lol.
I don't think any company really specialises in one model of pistol, I'm pretty sure they all use the same mechanisms just reworked to fit a different frame.
