Don't know if this is the actual name for it , but I like the kimura sweep. Going for the kimura, you can't get it so you keep their arm trapped and sweep 'em.
Hip bump/sit up sweep.
Very effective, I love it.
My current favorite sweep is actually one from DLR.
Sit up, pull their far arm between their legs and grab with your inside hand, use your outside hand to grab shoulder/lapel/belt and roll over the trapped arm.