Earlier today Which? Magazine posted an info-graphic on their Google+ page which showed the results of their smartphone battery life tests.
It should be noted that this does not take into account overall battery life (how the battery degrades over the handsets life span), which is why the HTC One is bottom of the charging speed chart after HTC took the decision to prolong overall life by reducing charging speeds.
However there is certainly something to be made of charging speed, the iPhone 5 charges the quickest, but has nearly the worst call and internet usage battery life. Personally I would rather have a slower charge with a higher usage (and prolonged lifespan), especially on devices with a fixed battery.