Depends on what you like about Fallout Tactics.
If it's the turn based tactical combat - then check out Jagged Alliance (1 and 2) and X-com 1 & 2 (available from Direct2Drive, Steam, etc.) Also, the UFO:Aftershock series (there are three) are pausable real time versions of X-Com, but have the same skill development and expansive weapon choices.
Not much in the way of "new" titles as turn based combat isn't fast enough for the newage fancy graphic dependent twitch gamers out there. Too bad :(