Just ordered the small pack of Lemon Tailwind. I'll give it a shot when it shows up. I've been using Accelerade for years (and the big jug seems to last that long), but don't mind trying something else out.
Nuun tablets seems to work well for me, too, but I often just use water to refill once I'm out and about.
I've got a buddy that swears by Skratch Labs, but he's also a Rapha nut and bakes his own energy bars and you know what they say about them...