Puerto Vallarta is a great place to visit if you want to get away for a short vacation (3 or 4 days).  A lot of the resort are fairly inclusive so other than walks to the downtown area for the standard souvenirs you can relax and be pampered where you stay.  If you do venture from your hotel/resort I do recommend a ride on one of the booze/snorkel cruises to Los Arcos and one of the jungle horse rides.  A few great hotels that I like are the Melia, La Jolla de Mismaloya, Westin Regina and the Plaza Las Glorias.  Where ever you stay make sure you hit the hot tub with a margarita or daiquiri and enjoy the sunset.