The Raistlin Chronicles actually take place before both the Chronicles and Legends series, but if you became a fan of Raistlin and Caramon from the Legend Series then these should be next on your list.
Matt says this series is EXCELLENT! Though they take place before the Chronicles; they will spoil the Chronicles if you read these two first. They do provide some intriguing insight into some of the things that went on in the world prior to the War of the Lance, and they are extremely interesting on that level -- in addition to being great stories.
Legendary Heroes and Villains
The following series here goes in-depth with the legendary heroes mentioned in the other books as well as the Villains.
The Legend of Huma and Kaz and The Minotaur (both by Richard Knaak) are excellent books. Matt also liked Weasel's Luck and Galen Beknighted by Michael Williams, although others would disagree with these two picks.
This series gives you the stories of those legendary heroes that were mentioned in the other books.
The Legend of Huma
Kaz, the Minotaur
The Gates of Thorbardin
This series contains the stories of those villains that were mentioned in the other books.