Everyone has given the staples of the genre so now for something completely different...
Brian Lumley has a series out on adventures in Lovecraft's dream-cycle... It is lighthearted adventure, a decent read. I believe there are at least three in the series, though I have read only the second, Frozen on ??? (The name escapes me at the moment). Lumley's Titus Crow series is also an interesting take on Lovecraft.
Not exactly high fantasy, but two good books I have read of late are southern/vampire/psychic/mystery stories. They are Dead until Dawn and Living Dead in Dallas by Charlaine Harris. Not heavy stuff, but it fills an evening with reading material.
Another light read, this one fantasy, if you can find it - Karena Brush's The Pig, the prince and the unicorn
Patricia A McKillip's Harpist series, beginning with Riddle Master of Hed I always find somewhat enjoyable. Likewise Terry Brook's works normally pass the time.
And then finally, if you want a thought provoking yet well written book you can't beat White's Once and Future King