It is not a single series per se, but if you want to read some great old school high fantasy, you might want to look into the
Ballantine Adult Fantasy Series that was edited by Lin Carter. There are some terrific fantasy books written by some of the greatest fantasy authors ever. Many of them are available in e-book versions but sadly not all. I have read the majority of them and found them all to be very enjoyable reads.
Also, though many of them are aimed at a younger audience, over the years I have thoroughly enyoyed Andre Norton's Witch World Series. IMHO, many of the later books in the series do fit into the high fantasy category.
Here is the wikipedia link if you want to look at the list:
http://en.wikipedia.org/wiki/Ballant...fantasy_series