Does DAI have the worst DLC? no. Not even close. Does DAI have the most disappointing DLC? Yes. Absolutely.
Pinnacle Station and Feastday Items are without question the worst two DLCs Bioware have ever produced. Followed closely by Darkspawn Chronicles, Golems of Amgarrak, Return to Ostagar, and Witch Hunt.
Soldier's Peak, Lelianna's Song, Arrival, Bring Down the Sky, Normandy Crash Site, Firewalker, Genesis 1 and 2, the DAI Multiplayer DLCs, and the various Weapon and Armor packs for all the games would be next, moving from the bottom up.
Stone Prisoner, Overlord, Omega, Jaws of Hakkon, The Decent, Zaeed The Price of Revenge, and Mark of Felissa Day would be next after that.
From Ashes, Kasumi Stolen Memories, Leviathan, and the ME3 Multiplayer DLCs would be here, right below the top tier.
Finally, the best Add Ons would be Awakening, Legacy, Citadel and of course Lair of the Shadow Broker.
The DAI DLCs are not the worst, but they are the most disappointing. They are disappointing because I had high hopes. DAI is a great game that is bogged down by serious flaws. Despite these flaws I found myself loving most of the experience and was really looking forward to the DLCs. What we've been getting does not live up to their previous track record for DLCs. Bioware DLCs, when at their finest, take the best aspects of the base game, crank it to 11 and add new, unique mechanics. Lair did this, Citadel did this, Legacy did this and Awakening did this. Jaws of Hakkon and The Decent are not bad DLCs. Are they overpriced? Yes I believe so, but they are not a net negative. The negatives cancel out the positives 1 for 1. They are 5 out of 10's. These DLCs did not really innovate, they didn't really try anything new mechanically. They instead follow the path of "more of the same." You could argue the combat of The Decent is a change in mechanics but....really all they did was create damage sponges and slapped a crap ton of immunities on them. The plots were nothing to write home about. Same crap DA DLCs have always done.
Vague hints about big, super epic mystery's that may or may not ever get addressed. They never really addressed Golems of Amgarrak, they just reused the asset in DA2 in a totally unrelated event. The DLC was literally pointless padding that served zero purpose. It foreshadowed nothing, it built up to nothing. Witch Hunt is very similar, A DLC that served little purpose beyond teasing the fan base, only to once again tease the fan base again in DAI, about the same damn thing, and just remove the character it was about after only 2 scenes. The DLC basically also amounted to nothing. Mark of Felissa Day has so far amounted to nothing, it's only purpose being to show off Orlesian Culture, fashion etc. That might be fine for some of you, but I want more relevance from my DLCs. So far Legacy is the only DLC that has been relevant to the DA setting, the only one that has done anything with the concepts it introduced. Even Awakening, as great as it is, has so far had zero impact on DA's setting.
I am disappointed by DAI's DLCs because they are following the same pattern all those others did. They just keep introducing and teasing more and more "massively, world shatteringly, unbelievably huge!" secrets and mysteries that continue to slowly but surely re-write and retcon the entire written history of Thedas, because "GOTCHA! ALL the stuff we wrote before was TOTALL BULLSHIT! Surprise!" On top of all this, they just keep piling it on more and more with present day stuff too. "omg Qunari invasion! omg Royal Succession crisis in three different countries! omg Grey Warden Civil War! omg your companion/love interest was the real bad guy! Speculations for everyone!!!!111!1!". Every time they release anything DA related. Books, comics, games, DLC, whatever. They almost always answer about one or two questions, but always give us like 10 more. This cycle just keeps going. We're up to about 5 answers with 75 questions. That in itself is not a bad thing, leaving cliffhangers and dangling threads can be good. But somehow I doubt they ever plan to address them all, or even half of them. Their track record suggest they just throw out about 10 things until 1 of them sticks. They then drop the other 9 and run with the 1. This has the potential to create a really big mess. This is why I find the DLCs a disappointment. It is just further proof of a pattern that worries me about DA's future.