Be aware that the generally accepted DPS build for ranger (and its elite specialisations) is a Condition Build though and it is not as easy to properly gear for a condition build as it is for a Power Build so it might take a bit longer until you are accepted into groups for the harder challenges in the game... (It wouldnt matter much for early/easier core game content but i dont know what your goals in the game are and how casual or not you like to play)
But ofc you shouldnt let that stop you from playing ranger though if you feel like trying that class since the class itsself has viable build options its just harder to gear for it
My personal advice would be: Try Guardian first
The Heart of Thorns elite specialisation for guardian is a powerful DPS build (power dps - not condition dps) and not as hard to learn/play as some other classes & builds might be.
It is fun and useful for solo open world & story instances play but also a welcome DPS class for group content later.
I wouldnt recommend you Mesmer/Engineer as your first class unless you really want to try it and are fine with a bit more complicated build (and support/tank role if you play mesmer)
A good answer depends a lot on whether:
you rather play casually or want to try out the hardest content in the game too?
you rather play solo or seek group play actively?
you rather play PvE or PvP?
you start with only the Free to Play Version with core builds only or you have access to the Elite specialisations because you bought the game?If you can tell us what kind of player you are (even if its just the info that you like to try it all) then we can give better advice for your first class And if you feel interested in a specific class just ask about it and i will try to name you all of its advantages/disadvantages in each part of the game and situation
PS:
Mesmer highest DPS that Izuku mentioned was mostly due to an unintended effect on a certain skil which lead to attacks hitting twice which was fixed just now so its just normal dps now
This post was edited by Kartoffelgratin on Nov 29 2017 03:10pm