I tried ranger when the game released. It is the most boring class in the game. Its special mechanic of pets is very uninteresting and offers little when compared to elementalist's element swapping. Bows, which should be what rangers are best with, suck. They lack utility in a group and are not anything amazing in pvp, that is to say if I were making a party I would take any class before a ranger. On top of all that, they seem to be the preferred class of botters everywhere. They are good at solo pve, but so is every other class as solo pve is really easy.
Go with the elementalist. There is more to do during a fight. Their class mechanic gives them a good deal of options. They have more abilities than any other class in the game. They feel much more unique than rangers. They are more useful in a group situation due to some pretty decent support skills and traits as well as solid aoe. They are harder to play well and don't get boring as easily as many other classes. They could use some balance adjusting.