cant speak much of DF1 as i didnt play it online. i only have it becuase of the 10th anni release.
i started in DF2 in nov '99. i do still play but not as much as i did back then. i was involved with the TXP2 mod that was never released, but most of the assets were released to tomkat for his DF2 EVO mod and a bunch of people play in that server.
DFLW i reached the level of 2nd LT in my 1st go 'round in 2000 or 01. i played it before NL banned the MM1 from the game, lol.
dagger: i didnt play online. played a ton of coops, especially all those darn =M= coops.
BHD.....played ever since the beta demo was released. even ran servers in it and the full release for years. SFH HELLZONE. i still am not a 100% fan of TS, but it was part of the evolution, so....
JO/JO:E: played almost from day1. twin islands demo was wild. the volcano map was cool. then when jo:e was released, spent many hours in the beta tests. coop maps were tough, but NL caved to the whiners and nerfed them into what the stock coops are today.
dfx, didnt play much. got the game for free.
dfx2, same. got it for free but did participate in the beta tests. pretty much showed the testers how to blast a chopper out of the sky when on an emplaced .50 cal when it was still 300+ meters out(thousands of hours playing coop helped, lol).