I was a big Hammer user...most flavors are really good save just a few (tropical and Huckelberry come to mind). I got some High5 gels in a pack from ProBikeKit and I was instantly hooked...MUCH thinner, super easy to drink rapidly, decent taste (kinds like thicker fruit juice)...far less messy and quicker than most brands I've tried. They use good ingredients as well. More than likely not as organic as Hammer...but who knows, High5's stuff is not labeled for sale in the US.
On a side note, Hammer HEED is horrible...High5's drink mix is so much better, it's unbelievable.