I enjoyed playing Renegade online for over a year when it was popular, the singleplayer wasn't great but the multiplayer was the best part, there is still a community that play although it is somewhat smaller than before. I ran a Renegade modding website for a few years (renhelp.co.uk) but the maps that shipped with the game were the best.
I moved onto Planetside after that with the guys I used to play Renegade with, that was a really fun game and I wish it was still popular because there hasn't been anything like it since (MMOFPS). It was game that you could just hop into and play for a while. That was a real team based game because you were esentially locked into skills you had chosen previously. I played as a combat engineer and advanced hacker with support vehicles who would scout ahead and capture towers and setup forward attack points. The mosquito aircraft was by favourite vehicle because it was so easy to fly and you could land it nearly anywhere plus you could do a radar sweep over an enemy base to determine how many people were there before moving you entire attacking force.