Any good cache cleaning apps? 'Must Have' apps?

[stimulatedboredom]

Those who have spent some time managing their applications, RAM and available internal storage have probably already noticed how quickly programs can eat up internal memory.

Has anyone found a really decent and easy to use cache cleaning app? Looking for one that is of the 'one touch' variety like Task Manager and Advanced App Killer.

Also interested in any suggestions for 'must have' apps, as the Market can get a little overwhelming to find gems unless you are searching for something specific.

Thanks!