A simple mark & sweep or stop & copy GC. Collectors which are incremental (work in small steps, not one full pass at a time) and/or generational (using several smaller generations, which are collected individually) break up GC pauses into something less disruptive.

For a good overview, read "Uniprocessor Garbage Collection Techniques" by Paul Wilson (check google scholar). Richard Jones's _Garbage Collection: Algorithms for Automatic Dynamic Memory Management_ is more in depth.