Heroes vs. Villains is my favorite but it has returning players from seasons 2 (The Australian Outback), 4 (Marquesas, important for season 8 but not for HvV (season 20)), 7 (Pearl Islands), 8 (All-Stars, fairly important for HvV but features returning players from seasons 1-7), 10 (Palau), 11 (Guatemala, not that important), 12 (Panama - Exile Island), 13 (Cook Islands), 15 (China), 16 (Micronesia - Fans vs. Favorites, another really good season featuring half-returnees and half-new players; returnees come from seasons 7-15), 17 (Gabon), 18 (Tocantins) and 19 (Samoa).
Out of the all-new player seasons I'd recommend Cagayan (season 28) or David vs. Goliath (season 37) the most.