Possible non-sport suggestions:
>Hedgewars (fan-made Worms clone, actually good)
- easy to follow, can be commentated
- games last a decent (and decidable) length
- lots of customization potential, including visual stuff like team uniform sprites, themes and importing images as playable maps.
- not boring or inaccessible
downside: no tactical input from boards
>Totally Accurate Battle Simulator (or UEBS?)
- looks fun and interesting
- boards could plot troop locations on half of each symmetrical map (with a set budget) before the comp and then be randomly played against each other using their predetermined troop positions
- appears to be reasonably moddable
downside: matches can be short if the battles are too small and if you don't abuse slowmotion, I guess
downside: setup time?
>Age of Empires or similar
could go on for too long...