For anyone who liked the original 2 Fallouts, I'd recommend Fallout Tactics and if you want to go nuts about it Wasteland and even Fountain of Dreams are pretty good.
I have yet to get into Diabolo, but that will be my next game. I couldn't get over Warcraft enough to embrace Diabolo. Coming from Blizzard it just seemed like a non-canon waste of my time. I can see now that I was wrong.