Saw this online, but Brandon Routh would be a good Reed Richards.
I think definitely having characters in solo and/or teaming-up with another character can display different sides to them or show them off in a way you're not used to when they're in their normal setting/team, although I don't think Sue was that different in the Deadpool story compared to normal, it was just her personality and powers contrasted with Deadpool's personality.
I think Reed can definitely come off differently depending on the book. The Illuminati are very different for him compared to when he's with his family, his talk with Daredevil on theology, etc.