I thought Auto Memory did a good job. You may want to check that one out Matth3w, it works with Droids own already well managed memory system to assist in deciding when to shut down task but it's not a task killer of any kind. I felt it helped saved battery when rooted.
Auto killer, auto memory manager, and min memory manager, do the same things. They're basically they same programs wrapped differently with their own set of features. I've used auto killer in the past but it kept fc on me so I'm using auto memory manager now. Honestly I don't know if I notice anything, but I guess that's because it's native android? Lol I dunno I keep it running anyway hoping it does something haha lol.