My best recommendation is Lawrence Watt-Evan's Esthvar series. Starting with the Misenchanted Sword. A very light hearted series and a fun read.
http://www.amazon.com/The-Misenchant.../dp/1587152827
Book 1 is The Misenchanted Sword (about your average soldier who gets a super-powerful sword enchanted, except with some flaws).
Book 2 is about a Wizard's apprentice who ends up on an adventure and he only knows a single spell.
Samples chapter on his site:
http://www.ethshar.com/themisenchantedsword.html
http://www.ethshar.com/withasinglespell.html
Mary Gentle's "Grunts!"
http://www.amazon.com/Grunts-Mary-Ge...grunts+fantasy
Orcs get modern weapons from a Dragon's Hoard. The "curse" gradually turns them into movie-cliche Marines. I seem to remember this is pretty funny if you like fantasy parody.
Edding's Belgariad is pretty light-hearted/humorous also.