Also, Grizzly River Run and CA Screamin'. And often on Tower of Terror, they will look for guests checking in alone. You go through the rest of the line with everyone else, but when they are loading the elevators they may call out for single riders.
Even though Soarin' has a single rider, most times you'll be better off using Fastpass. The single rider is a hit or miss, but every time I've tried it, it has taken more than 30 minutes to get on.