Ugh...yes, that question again....
It depends on what expansions you have (or none). You can check out the Elite Specializations for each Profession, and see if any tickle your fancy.
https://wiki.guildwars2.com/wiki/Specialization
https://wiki.guildwars2.com/wiki/Specialization#Elite_specializations
There are links to videos, blogs, etc. on the page (or found in this past week’s News Blog).
Good luck.
https://www.youtube.com/user/MintyMike26/videos Mike has a decent “intro to classes” series to get an idea of the classes….. but I would like to point out that Especs require a dedicated discussion, because of the way they change class mechanics in this game. Like in a big way.
To investigate each Elite spec, I highly recommend taking the time to look for a proper break down video, as 90% of Espec videos tend to focus on meta builds.
From there its simply a question of your personality. It doesn’t work to use vague terms or concepts like “I like being a healer” or “I like to tank”, because every class is pretty broad spectrum when it comes to potential builds, and the game doesn’t like the tank/healer/DPS Trinity as a concept. Classes in this game extremely flexible; and even the narrow mindedness of the meta still manages to turn the idea of a Raid comp on its side. Like how the current meta has Mesmer as the top tier tank, despite Mesmers being a utility caster by design.
Don’t forget; you can jump in the Demo right now and try out all the new Elite Specializations coming with Path of Fire. You can try out Core Specializations there, as well, or with any character in Heart of the Mists.
If you have a L80 Boost and Heart of Thorns, you can try out HoT Specializations (all nine), as well.
Good luck.