I have a hard time ranking them because quite frankly there are some contextual differences. I like some packs in heroic, others in epic/legendary. Menace of the Underdark and Shadowfell Conspiracy are pretty solid in epic (and, in fact, almost mandatory) but sometimes I just run legendary instead of epic and don't touch them.
I think my easy favorite is Mists of Ravenloft. Great design, classic module, strong presentation, good gameplay, loot is getting a little long in the teeth though. That said, I have no real complaints about Mists other than a few nitpick level complaints.
I actually really like the Chill of Ravenloft too. I think that might mostly be because I don't mind the "flavor" which a lot of people seem to actually dislike. I feel like the quests are reasonably interesting, there's a couple I don't love but I overall enjoy running the saga both in heroic and legendary which is a positive. The wilderness area lacking good teleports hurts, but it's also pretty easy to navigate and decently sized, so I think it's fine. The loot situation is dire, though, with both rare loot and sun/moon table clutter making gearing frustrating. I personally actually don't find Chill to be that frustrating because I don't personally think most of the rare loot is so extraordinarly good that I miss out on it, at least in heroic where I find myself running Chill more (I run it in legendary but I just am not as fussed about legendary gearing with level cap increases down the road), at least compared to MD. But I understand why people might dislike Chill because of that.
Vecna Unleashed is one I see get a lot of hate. There's some issues with Vecna- some polish related issues, some level design issues, and so on. However, I quite like it for an 18-20 on a heroic life, so I run it quite a bit. There are some issues of course but I think the quests are at least relatively diverse and interesting. I don't like the absurdly tanky skeletons, the quest for the Dark Six if I don't have evasion, and some of the poorly recycled assets, but I wouldn't say it's bad just because of that. If you treat it as a slightly smaller expansion (no wilderness area) I think it's nice, and I do actually really like all the quests being in town walk ups with no lock-outs- it's a good quality of life for repeated playthroughs on subsequent lives. I also think the story is underrated- I am Vecna's biggest hater and I actually dislike IoD because of Vecna's presence and I still like Vecna Unleashed because the heist, the university quests, and the various deity quests are great flavor and variety.
I only run MotU and Shadowfell if I'm doing epic sagas. I have nothing against them, I just don't think they're particularly rewarding in 2026, with all the named loot being basically obsolete, dated content with relatively boring gameplay (balanced around a much older DDO where numbers were a lot smaller) and quite frankly I've just run them so much that even when I don't touch them for a year I remember basically every moment of the chains when I eventually crawl back for epic experience. But with the sagas they are a great epic experience source, so they're definitely easy to recommend.
Sharn is one I like, but mostly in heroic. I don't know why but I don't think I've ever actually run legendary Sharn. I probably have and just don't remember it. One thing I've noticed is that Sharn kind of feels too long to me- I'm losing investment in the story by the end of it. I think it's just a few quests that feel very forgetable that drop out. I think of all the expansions Sharn has one of the weakest storylines, despite Sharn being a perfect setting for an expansion. Each individual quest feels fine but it feels contrived and I just don't get enough buy in to care about the story.
Isle of Dread is relatively low for me. There's a lot of unskippable cutscenes, a lot of relatively large quests that just aren't populated enough to justify it, and while better than MD the wilderness area wastes a lot of time. That said, it has better teleports than MD. I dislike Vecna as a villain and it does negatively impact my opinion of this pack, but even accounting for my biases I think it gets a lot more praise than it deserves. It's... fine. I don't mind running it, but it also seems to be full of a lot of things people hate in newer content that somehow gets a pass here, like mandatory cutscenes, big wilderness areas with poor transport, etc. I'm not saying you can't enjoy Isle of Dread but I think it gets a pass on some things and I personally don't know why.
MD is rough because it could be good and the things holding it back are own goals which would have been easy to fix. MD is really hurt by having a wilderness area the size of an entire state with very little to do in it and poor transportation to the quests. I think if the quest entrances had Mists of Ravenloft style teleports, I would actually bump this expansion up significantly. I like the classic D&D setting, I like the story, I enjoy most of the individual quests (bar TLP), to the point where I rate the pack a lot higher if I use my VIP skip on that quest every time. Also, several of the quests just feel artificially padded with extraneous corridors, which is boring. Rare loot leaves a bad taste in the mouth, and while I personally ignore rare loot I feel like it's unfair to rate the expansion higher because I just put blinders on so I can enjoy the game more fully. Sun/Moon augments exacerbate this on the loot list. I would put it relatively low just because a lot of the pain points are just bad design decisions that could have been avoided, but were not, and missed potential is more offensive than just a bad concept.
Saltmarsh is weird because my opinion on it is very mixed. Parts of Saltmarsh feel great. Others feel like pure suffering. If I never have to visit the lizardfolk village and save the princess or whatever again it will be too soon. But the wilderness area is fun to explore, and while I do think some of the quests could really use fast travel Saltmarsh doesn't feel as awful as, say, MD. I don't put it down here because I feel negative about it, but because it doesn't neatly fit into the way I categorize expansions in my head. If there are specific things I want from Saltmarsh, I don't mind running it, but I often would prefer to avoid parts of it just because a couple of the quests are poor time for reward and outstay their welcome.
Feywild is one that I have to make a guilty confession about: I bought Feywild, played it once or twice, barely remember it. I don't hate it. I don't think I ever made an intentional decision not to play it. I've hopped into a quest or two here and there and had fun. I just... never run it. I keep meaning to change this, then I never do. I have no idea why. The wiki has everything I need to learn the quests, I like the feywild conceptually, I don't remember having any "I hate these quests" moments while running it, and while I do hate Through the Tulgey Wood that is not part of the expansion (yet, for some stupid reason, I've probably run it *MORE* than the expansion quests). Basically, this one is on me, and it's at the bottom of the list not because I hate it but because, like Saltmarsh, it just fits into my experience of DDO in a weird way. I should force myself to play it and form an opinion about it.
Anyway, I wouldn't take this as a hard and fast list. I run MD at level, personally, and it's technically last, so this isn't a "I hate it and never want to see it again" post. Generally speaking I think most quests in DDO are fun and I haven't had the opinion that any of DDO's expansions were not worth running. I definitely have my favorites (Ravenloft and Ravenloft, which maybe says more about me than about the expansions- I do like a good fantasy horror setting) but none of the expansions are, in my opinion, particularly bad. Or maybe I'm just easy to please.