I vote either...

A) Clan Invasion, 3050. It's just got all the plot we need: the Space Mongols (the Clanners) are coming and it's time to kick them out. Good plot; good lore; good setting.

B) Something more "modern" in Battletech, but taking place with us as mercenaries in the Periphery (I.E. away from the chief politics / civilization of the setting, probably more "Wild West" esque).