I'm pretty sure CPython reference counts objects. Also Objective-C -- as in GNUStep, if you aren't using a Mac server.
EDIT: There's a downside to reference counting in that either you or the runtime does the retain/release calls very often, whereas a mark-and-sweep collector would just touch each object once per collection. So reference counting might not be faster overall, but typically avoids long pauses. What you probably really want is something like Azul's JVM, which has a kernel extension so they can collect memory concurrently, resulting in shorter pauses than sweeping and faster overall time than reference counting.
EDIT: There's a downside to reference counting in that either you or the runtime does the retain/release calls very often, whereas a mark-and-sweep collector would just touch each object once per collection. So reference counting might not be faster overall, but typically avoids long pauses. What you probably really want is something like Azul's JVM, which has a kernel extension so they can collect memory concurrently, resulting in shorter pauses than sweeping and faster overall time than reference counting.