[spurgu]

Personally I always go with Cache Enabler (by KeyCDN) with nginx. Simple and rock solid. Creates static HTML. For optimum performance (bypassing PHP altogether) configure nginx to try_files (or equivalent in Apache) in the wp-content/cache directory.

Edit: I've also used WP Super Cache and W3 Total Cache quite extensively, both both of these have on some sites had a tendency to randomly clear the cache and I've never managed to figure out why. Cache Enabler has never done this.