besides, there were a bajillion or so daves, more then four i know that for sure. I'm surprised you all knew which one the OP was refering to as the first game.
Nope. There was just three ports of the first game (including an unfinished one) and a tech demo called "Dangerous Dave in Copyright Infringement" plus of course the trilogy that we have on GOG now - so it's really just four Dangerous Dave games. Any other "Dangerous Dave" games you may have come upon are unofficial.
Oh yeah, did some research, there was indeed one more game called "Dangerous Dave Returns". It was just the original game with another set of levels and exclusively released on Apple II it seems. Any other releases are ports of sorts though ("ports of sorts"... haha).