Deathspank

An addictive and semi-challenging Action RPG (you don't need to grind, you'll level up normally while doing the quests, but you have the option of grinding early on and hunting the stronger enemies that you will face later in the game). Almost all of the quests/puzzles are fairly easy to solve even though they're not linear (e.g. you'll take quest A B and C at the same time but you'll only get the solution for quest A once you finish quest C).

Also, the script is hilarious. It pokes fun at other RPGs. It's got the same brand of humor as Secret of Monkey Island and Psychonauts.