An incredible plot, solid campaign, and decent multiplayer makes Pacific Assault probably the best in its series.
While you are Tommy, you'll fight through the islands of Makin, Guadalcanal, and Tarawa, and even attempt to survive the deadly attacks on Pearl Harbor. The plot enrolls beautifully and helps you sit through the sometimes long cutscenes without wiggling in your chair.
Here are the good details: it has an incredible plot, solid campaign, and decent multiplayer. It also has a pretty good interactive main menu, too. (yeah, the main menu is one of the high points for the Medal of Honor series)
Here are the few bad ones: It lags a lot when you first jack in to the Pacific Assault engine, but the more you play it, the less and less it lags, and soon it won't be lagging at all. There are a few bugs that are nothing to overreact about.
My recommendation: if you like kicking it old school and laying back to some lower-gen PC games than those that are out on the GameStop shelf, than this is definitely worth to try out.