Have you read Raymond E Feist's Riftwar series and the successive books all set in the same world? That is my favourite serious fantasy series although Scott Lynch's Gentleman Bastards Series is catching up fast.
have you heard of the Malazan books? Steven Erikson? (I don't know if I spelled any of those correctly). I heard that stuff is really good.
I haven't read any of these but I'll check them out.
Another good fantasy series is George RR Martin's " Song of Fire and Ice " series.