Limes are my faves, especially a variety that we have down here in Ecuador called Limon Dulce, which has bright green flesh and is sweeter than many oranges. Very good as a limonada, in Cuba Libres, and to make cheesecakes. (And don't get me started on Ecuadorean Spanish terms; Limones are Limes, and Limas are Lemons....)
Voted for Limes - have the nicest fragrance and taste the best in a Gin and Tonic :D However, if I was able to vote second and third, I would vote orange then lemon. Oranges taste so good and lemon blooms smell wonderful.
The taste of a Floridian Ruby Red grapefruit brings me down on my knees, and the succulent and sweet tiny honey mandarins are a delight...then, there is the sweet Meyer lemon that you just plucked off your tree... what a treat!
I'm with K.Baron on #1 grapefruits/pommelo some are unbelievably luscious #2 Satsuma mandarins #3 Minneola tangelo