Of these, the third photo is clearly the best. (And to my mind not only the best of the bee photos but of all the little series shown here). It has a depth that not even one of the two singular flower photos has, despite the fact that the two yellow flowers are also nicely detached from their background by choice of aperture, the placement of the bee is in one of the best spots to place a small subject, and there is only that mild bit of "wind shake" (looks like there was a bit of a wind going making the flowers move). The other two bee photos have too much shake over all for my liking. They're kind of hard on the eyes.
The first photo has great potential and the only nitpick I really have is the dead leaf in amongst the flowers, which is a bit disturbing.