Season two he was just getting his footing, and season four was his leaving season. Season three he was awesome.

I like him in Two&Three.. I picked two though because when he started he acted all cool :]

Season 4 Oz :(. Marti wrote him into the place she always wanted him to go.

season 4 oz was bad i liked him in the first couple episodes of it though i still loved him but nowhere near as much as i did in the other seasons
season 3 was awesum for OZ he was right in the action i love in Anne when he throws the stake in that flippy thing but it hits the rock and hes like"that always works in the movies" and in season 2 when hes all embarrassed about save willow his anmal cracker line"i mock you with my monkey pants"

I loved him in 2 and 3 but more so 2 cause he was just starting and his character was secretive and interesting. :D

I think he was cute in two and while it's a fantastic storyline and I like watching it I don't like his character in season four. That said I have to go with season three, he's a very good mixture of cute, loyal, funny, and passionate about Willow. Watching the reactions to her in danger is always a good time because he's so mild that a spark is fun.