Thinking about playing again, need class advice

What the title says. I used to play Monk and Ritualist. Monk was great for parties, sucked playing with the AI, and I expect to mostly play with the AI since 7 hero parties are in (AAAAAAAHAHAHAHAHAHAHAHA AND THEY SAID IT WOULD NEVER HAPPEN) and while Ritualist was decent for parties and also decent for AI once spirits got buffed, I'm not sure it's the best class to play.

I don't know how the metagame is standing; I don't really want to look over builds and whatnot just yet; I'd just like to make a character and play again, but to be making one of the right class.

So, the question - what class is best for vanquishing / HM missions with the AI? Is a physical melee damage dealer still the best choice?

IMO, yes, a melee character is best. You can run a caster anyway with how overpowered skills are these days, but I prefer running a melee character myself as heroes can't be trusted to do it. Hero AI is terrible for melee, but amazing for casters. Also, I feel being frontline gives you better control of aggro. Hope this helps. =)

Assassin or warrior?

Last I played, both worked pretty well, with Assassin probably being the better class. Is this still the case?

Dervish, but that is just my option

I'd go sin, they get into all the high-end stuff I think

I would say Rit..

Factions is fastest campaign to lvl a character.
Rit is a versatile class, can tank, deal damage, Spirit Strength allows U to play melee and do good damage.
Rit plays in almost all speed clears (FOW, UW. DOA, most dungeons)
SoS is always wanted in every team build, in any area

Mesmers are very powerful in both PvE and PvP now days so it gives you some flexability to your style of play. Mesmers also have a wide range of skills to keep gameplay fresh.

Also while melee classes can be fun to play not many are accepted into SC due to current metas (With the exception of sin with sf ofc), so replayability can be affected if thats where your heading...But thats just my opinion.

Even though I'm sure OP is longer looking at this I would say
The Super Chilli is correct Mesmer's are very over powered and always a better choice than any other caster class. The Exception being a Rit of course ....

Im in the same boat (mostly back for HoM) and i chose assassin. The kicker is Shadow Form honestly, which i suspect will come in handy farming for certain titles.

Assassin is fun, though. Some people say 1-2-3 BD spam is boring, but i beg to differ. The fun thing about it is your elite can be anything, really