Ladies and gentlemen, may I introduce you to...the Coffeegasm[sup]©[/sup].
Mix Baileys cream, a little vodka (optional for extra drunkeness), Tia Maria, and a small amount of either ice cream, preferably vanilla (Slightly melted), or double cream. If you're using Ice cream, blend it really really well. Once it's a slightly thick, smooth liquid, enjoy. Having vanilla extract on hand if you didn't use the ice cream can really help.
I was feeling inventive one day, and haven't looked back since. God damn it's good.