I love Severitus and I know tons of Snape-mentors-Harry type fics. They were where I first started. Funny how your HP fandom life is an exact reflection of my own! *hugs you fondly

My recs are from a while ago, since I've moved into HG/SS now. There are probably more recent ones out there that I don't know. But these are all classics should keep you busy for a while :-)

Resonance by GreenGecko (darkirony) and its sequels, Revolution and Resolution are definitely epic-length, beautifully written, addictive.

In Blood Only by EM Snape, already mentioned above.

Harry Potter and the Battle of Wills by Jocelyn (jocelyncs)

Blood Magic by Gateway Girl (gatewaygirl)

Go with the Tide by Tantz, and its sequel, Go with the Tide II: Seeing is Believing, which contained inspiration for the latest chapter of Iridescent Snow, by the way ;-) (Which you haven't read yet *teasing sniff)

The original Severitus that started it all: (but be warned, it's an abandoned fic)--A Father's Sin by Severitus

The mother of all Snape-mentors-Harry: A Year Like None Other by aspeninthesunlight (aspenlight), for which I've actually written fan fictions of the fan fiction (my first foray into fic-writing!) Song from the Heart, Interregnum, and Drowning.


*bows

Enjoy :-)