I love playing around in DADGAD CGDGAD and DADEBE when I'm not in ol' standard. CGDGAD is an interesting one, Dave Evans (welsh folk singer/guitarist) played in it for a lot of his tunes. DADEBE is great and I've come up with a lot of songs in it - it's fairly close to standard but seems completely different at the same time. It's very close to the tuning for Nick Drake's 'Road' (EADEBE). Word of warning though - try not to go too nuts with the alternate tunings like I did a while ago. Standard is a good compromise and has incredibly far-reaching potential. Alternate tunings are great for coming up with ideas, but make sure you don't find yourself in a pickle. with ten songs in eight different tunings! ;-)