Get some Sup Com FA on that list and some UT2k4/UTC and you'll have yourself one hell of a list.
Planetary Annihilation?
These look good as well. Sup Com FA isn't too expensive either so I'll probably try that before PA I think.
Careful. The eco in sup com fa is confusing at first. A lot of people can't handle a supply / demand resource system. Personally, I think it's best (as in reality, you don't have an infinite amount of resource storage).
How would you say it is compared to SC1? I played that a lot like fifteen years ago or something like that. Does it require a high APM to be good, or is it more strategy?
You mean starcraft? Starcrat is unbalanced, which leads to 'spamming' keys. Supreme commander is the continuation of Total Annihilation, and it plays a bit differently. It's a lot less twitchy and lot more strategic imo, but that's not to say it doesn't have it's flaws.
Sup Com/ Sup Com FA allow you to pre-plan through templates, this helps you focus on whats going on rather than having to balance running defences/offences with building resources. You can just place the templates down and get to it.