Bishop Always wanted in bosses and Genesis is the best mob skill Like above, always wanted in bosses and parties because of Holy Symbol and Genesis training Everything is cheap to Bishops
Gene20 would like to have a chat with you The mastery books are still pretty affordable though. On topic: I agree with Plenty. Bishops are a great starting class, especially if you want to make some money, as genesis is really good for farming and selling leech.
Hero and Dark Knight are decent alternatives. You'll be able to hit multiple mobs and you'll do okay at bosses, especially at multi-target bosses such as horntail. Hero being the better DPSer but Dark Knight has the advantage of Hyper Body which is always appreciated. Both have pretty cheap books as well (Except maybe Berserk 30 but that one has dropped in price lately).
Take any mage for mobbing and farming. All mages can sell leech but Bishop being "better" because of HS. F/P has the best damage per hit though.