Found this quote by someone

Q2: besides the really terrible sound engine (poor attenuation and mixing), crappy blaster and hilariously slow weapon switch time, the game just 'felt right' to me. Everything from the theme, items, single player, maps, etc. is just great fun. It was a massive step forward in level design in its day. Also has a massive collection of community content out there, maybe more than any other Quake.

Q3: let down by no double jumping and no single player... but in its favor is a brilliant game engine (the best idTech yet, imo), good weapon balance, good built-in multiplayer bots, powerful level design features, some really good community maps, etc..

QL: doesn't have the same fun experience as Q3. Where Q3 could be played casually, this game has become far too serious and is all about winning and stat peddling. Add a good dose of player base segregation and the crappy browser based model, and you get a game that's just a shell of its original self.

Q1/QW: terrible physics, primitive map design, boring single player, ridiculous weapons. The game is all speed and not much else really. Not my kind of scene.

Q4: really bad community reception, buggy engine, laughable FPS cap, overdone normal + height mapping that makes everything seriously high contrast and distracting. The engine in its current state is only really good for single player, but even then, the single player is soooo slow and full of rage-inducing cinematics that even that is not worthwhile. The sound engine is brilliant though, but we have Creative to thank for that. As a game that is meant to be a successor to Q2, it wasn't very well executed thematically either. A step forward for idTech 4 would be to release the full source code so that major improvements can be made.




For me q2 was hands down the best (gameplay wise) - eg, the most fun.