If they were only going to make one more TNG character as a Minimate, I think Worf is the smartest choice. Aside from Geordi, who would need that sculpted visor, he's the only character that isn't a pretty easy quick custom. The yellow shirt, along with Picard's red, gives us fodder for everyone but Crusher and Troi. A sculpted brow piece gives us fodder for more Klingons, somewhat satisfying the requests of people who want alien army builders. And a Bat'leth blade would be all kinds of awesome.
I wonder what alien/villain they would pair him with? Another Klingon in battle garb seems logical. A small-body Ferengi could be cool, too