I think perhaps a catchy slogan is better as you keep the name intact and can always remove the slogan without much further ado should you decide it wasn't such a good idea after all (well it CAN backfire).
My advertisement manager at the newspaper had a FUNNY slogan one time but we decided against it just because it's a bit spicy but it was:
We sweat your grass off for you.
Then the other day I saw one which said:
If we didn't pave it, it's your own Asphalt.