A lot of people complain about how useless the pickpocket tree is, but I say it's worth it to make all the guards in Solitude walk around naked. 
Dawnguard was good and Serana is awesome, but the main goal of the vampires hinges on a giant cube of fridge logic (put out the sun, everything dies. Including you, dum dum.). The Dawnguard armor is sweeeet looking.
Then Dragonborn brings Stalhrim. I love the light armor version, except the helmet. Giant insect antennas. Silly.
And Heartfire gives the ability to bake potato bread... yes, it's a big deal! (tasty, tasty potato bread...)
Serana is awesome but the deficiency with Skyrim vs DAI comes right there. The interaction with Serana is great while you're doing that plot but it's so short that ultimately she becomes this drone that follows you for another sixty hours or whatever.
I enjoyed baking and planting gardens too. It was very zen like to do nothing in a game but build a house and then bake.
I've had Fallout 3 sitting in my Steam account for ages after I got it in the sale once, and I still haven't played it!
I do enjoy the wandering around and crafting in DAI, as evidenced by my huge playtimes, but I love the characters in BioWare games so much. That sense of companionship is what draws me back to their games again and again, I think.
I also have abandoned playthroughs of The Witcher, Bioshock and Bioshock Infinite, which I'm allegedly supposed to love, according to various people. I suppose I have peculiar tastes.
I was supposed to like Bioshock Infinite too and yet I found it tedious and shallow and never made it more than a few hours into it before I was overwhelmed by a sense of "why am I doing this?" I had a similar reaction when I bought into the hype for Dark Souls and a few hours in was asking myself "why am I doing this? I mean what's my raison d'etre here?"
In the BioWare games I've found the answers to "why am I doing this?" and I've discovered I need that motivation in my games. I need that reason to give a damn.