Map Size
I don't really have an opinion on map size as long as travel is convenient. I want to be actually playing the game, so something like BDO isn't that appealing to me. When traveling in that, I spent a ton of my time just alt+tabbed with autorun going. Compared to something like FFXIV I'm basically always able to do something because there isn't really much distance to run.
I do like WoW's travel system, though. Having things like the Deeprun Tram or just the portal rooms, where it takes you to a specific place and you have to cover the rest of the distance yourself is pretty neat, and lends to some creative ways to get around the world. But yeah, the map size itself isn't a big deal to me compared to travel methods.
Questing
I have virtually no opinion on quests, really, except that I prefer the quest grind to just killing monsters. I played a lot of Ragnarok Online and MapleStory in my day, and trying to go back to them nowadays I just... can't. I prefer doing quests and getting a lump sum of experience per task instead of a small amount of experience per kill. Story is irrelevant to me, I just like the quests as an experience delivery system. However, I prefer running instances even more. Love leveling my secondary jobs in FFXIV because grinding dungeons is so much fun compared to just questing or other methods. I also did something similar in WoW when leveling a Druid and just vastly outleveled my quests from it. Love instances.
Lore
I like lore. I prefer the world telling the story more than just text. I like seeing the impact of important events rather than being told about them.
Professions
Professions can be cool. I try to get my professions up in all the MMOs I play and I find that I'm constantly disappointed in them. I'll frequently get my professions up, but then be annoyed that there's rarely anything worth crafting. I have all these equipment recipes, but no reason to make them, for example. I enjoy Engineering the most in WoW because you actually get a lot of cool toys with it. I like FFXIV crafting because it's its own whole thing.
Player Impact on Story
I don't like my player character being important. #1 pet peeve with MMOs. I hate myself being an important figure because there are a million different people exactly like myself who are supposedly exactly important. Leave that to single player games in my opinion. That's why I prefer lore and world building. I don't care about me.
Combat, Art Style, POV
I prefer tab target combat. No real preference on art style, I enjoy all sorts of that. I prefer having a choice with my build, but with the knowledge that there's almost always an objectively best build it doesn't really matter that much to me. So I'm also okay with something like FFXIV where you have essentially zero choices. If given the choice, I like making my own builds, then cross referencing them with stuff I find online.
Character Customization
As long as I can pick gender, race, and some other features like hairstyle I don't really care that much. I hate things like BDO where classes are gender/race locked. That always bugs me no matter what. I don't mind having few options because usually the customization in MMOs comes from the armor, and less from how your actual character looks. So with that said, obviously transmog/glamour is mandatory.
Events
Honestly no opinion on this. I'm good with events like FFXIV where it'll take like 20 minutes per event to get everything, or stuff like GW2 where an event can totally overtake your gameplay for a while sometimes, or stuff like WoW's Darkmoon Faire where it's a super regular thing that's just a bit of silly fun or a few quests or something.
Classes and Skill Trees
I barely played WoW during BC (up to level 55 Ret Pally) and didn't play it again until WoD, and never really played anything else with skill trees, so I don't have any real experience with this. The #1 thing that's more important than literally everything else I said so far in this entire comment is that I can play a Rogue or a Thief. After that classes don't even really matter for me. As long as I can play Rogue/Thief I don't care if I have zero customization or infinite customization.
I will also say that I want enough customization to make sure I get the flavor or Rogue that I enjoy. For example, I love Rogues in WoW, but I don't enjoy the pirate theme, so Outlaw Rogue isn't enticing to me at all. If Outlaw was hypothetically the only option, I'd probably be a bit disappointed, but with Subtlety and Assassination it makes Rogue absolutely fantastic. With FFXIV, Rogue becomes Ninja which is a huge disappointment to me. I love Thieves, but I find Ninjas not appealing at all, so in that case I wish there were more options to be able to stick more with the Thief aesthetic. (I know Thief becomes Ninja in FF1, but even in FF3 I keep one of my characters as Thief the entire playthrough, plus they're different jobs in FFXI, not that I know a lot about that game).
And finally: what's your favorite MMORPGand which one have you put the most hours into (if they're different)?
FFXIV in first place (Over 3200 hours), Guild Wars 2 in second place (Over 2000 hours), and the rest is a bit hazy. Probably WoW in third place, but I've also played a butt ton of Ultima Online, Ragnarok Online, MapleStory, and SWTOR.
That said, I don't think I'd consider GW2 my second favorite MMO. I'd probably say WoW is my second favorite even though I'm fairly sure I've spent less time playing it. Mostly because I can see myself playing WoW again, but can't really see myself playing GW2 again.