So I'm finding Supreme Commander a very love / hate affair.  Don't get me wrong, there's tons to love -- huge armies, love the mega-zoom, lots of neat little mechanics and massive carnage.

But in order to effectively complete the second campaign mission, you have to know that secretly, control-alt-right clicking does a totally different kind of move order than normal right clicking (attack move & in formation vs scattered regular move).  This is clearly a contender for the worst UI award -- and I should know, I've worked on a number of games that are serious competitors on that front as well.

It's quite peculiar given how elegant other aspects of the Supreme Commander UI are that you have to do a largely undocumented doubly-chorded modifier click in order to do one of the most basic commands in the game. 

Don't let that stop you from checking out Supreme Commander though -- it's a different kind of RTS than the more tactical and small scale affairs represented by the Company of Heroes and Command & Conquer games.