Yeah, Robert Jordan is terrible. I tried so hard to read his books because my friend loves him, and nothing had happened after about five thousand pages, so I just stopped. I hope Rand burns in the fiery pits of Hell.

How hard is this to answer. Going for series rather than books though.

1. The Dragonlance Chronicles and Legends by Tracy Weiss and Margaret Hickman - fell in love with Raistlin when I was much younger.
2. Thomas Covenant series by Stephen Donaldson - Mordant's Need is also very good.
3. Belgarion/Mallorean by David Eddings
4. The Three Worlds series by Ian Irvine - can't believe no-one else has mentioned this!
5. The Wheel of Time by Robert Jordan - although have to say I'm getting a bit sick of it. Just want to know the ending now

Top five books, impossible--how about top 5 series/authors

1 George RR Martins "Song of Fire and Ice"
2 David Eddings-anything and everything
3 Raymond Feist-anything from Midkemia
4 Weiss & Hickman-Dragonlance+Death Gate
5 RA Salvatore- Drizzit (say no more)

it's hard not to mention the Anthony's, Rowley's, Brooks', Zelazny and many others that have touched me over the years.

I can't put them in order of preference, but

1 Ranger's Apprentice
2 Wheel of Time series (though they take so long to read that I can't be bothered reading them most of the time)
3 His Dark Materials series
4 The Inheritance trilogy is great (still waiting for the 3rd one though)
5 Tamora Pierce (anything, but the Alanna and Kel series are the best)
Excuse me for not mentioning HP, but the other ones I listed are a little better, still love the HP books though. (Going to see HP5 the movie tomorrow as well )

Other than that I read mostly sci-fi, and other fantasy books that are great but I can't remember them, so they can't have been that good.
On the mention of sci-fi, though off topic, I must give a mention to Matthew Reilly and Michael Crichton. Great authors of action/sci-fi.

Terry Pratchett is great but when it comes to top 5 I prefer books with a more serious plot. Love them for the humour though.

EDIT: arrghhh, how could I forget the "Sabriel" series by Garth Nix! They are added in as well. this has been a wonderful top...5 for me.