I haven't seen
VEX mentioned yet. I'm currently a college student mentoring a high school VEX team, and it works much better than FRC for me schedule-wise. Since the competition runs year-round, our team holds once-a-week meetings on the weekends, meaning that I don't have to sacrifice my school nights to come help out.
VEX also has a collegiate-level competition division you might be interested in, but I don't know much about it.