Long verses shorter rod handle.

[fishaholic18]

I like 24-25" to center of seat.

[baldwin]

You want enough handle so that you can rest the butt of your rod at your crotch and reel comfortably. Saves strain on your back when hauling in large plugs and fish for long hours.

[baldwin]

For surf rods that is. Sorry, sometimes I forget that there are other types of fishing.

[Terence]

Surf Rods only.
My back is always shot after 5 hours of surf casting.