I found this very useful information page about a list of wordpress caching plugins (http://www.tutorial9.net/web-tutorials/wordpress-caching-whats-the-best-caching-plugin/) and for me this wordpress caching mechanism seems to be the best one:
Hyper Cache is specifically written for people which have their blogs on low resources hosting provider (usually shared hosting). This is a html caching plugin.
a long time ago I've also used wp-cache. As written on the great side above, this wordpress plugin looks like as it 's not supported anymore. Actually I never had problems with wp-cache.
But be aware of any wordpress caching feature (plugin)! Usually everything works fine, but dont forget:
TURN OFF (DISABLE) THE CACHING PLUGIN EVERY TIME WHEN YOU DO SOME MAINTENANCE ON YOUR WORDPRESS SYSTEM!
Once ago, I made an upgrade of my wordpress and all plugins were disabled but not the caching (by mistake). This was no fun, my complete wordpress setup was a mess! After all I could delete all wp cache pluging files and after all I could disable the wp cache plugin itself. I will never make the same mistake again ...
Please see plugin notes: Hyper Cache is a cache system for WordPress to improve it's perfomances and save resources. Before update read the version changes. To manually upgrade remeber the sequence: deactivate, update, activate.