DAI DLC

Trespasser for sure. Jaws of Hakkon and The Descent are nice as well, though not nearly as good as Trespasser.

^This. If you are looking to continue the main story from DAI, you definitely want Trespasser. I found all three fun though.

That depends entirely on your play style and level of ability, but 3-4 hours from each DLC seems like a good bet if you explore them thoroughly.

Jaws of Hakkon is basically a large open area with an over-arching quest.

The Descent is a straightforward dungeon crawl.

Trespasser has the most story content and should be played when you're ready to retire your Inquisitor permanently.

JoH is really what the open areas in DAI were meant to be, it's really good.
Descent is cool but as a policy I hate the deep roads
Trespasser is a must play. Not only it wraps up the story but also it's damn good

Just finished trespasser.. don't really know how to feel about it.

It was good because DAI is good in general.. just still doesn't feel like a satisfying ending. Some dialogue seemed pointless too... but eh it was worth the money I guess

You would have better off getting something from Steam, because buying DAI DLC at full price is a rip off ($15 per DLC).

On Steam, Witcher 3 GotY edition is only $25 while the DLC expansion pass (for both the Blood and Wine & Hearts of Stone) is only $12.50.  On EA Origin the cost is double ($50 & $25).

Of course EA never bothered with an expansion pass for DAI.  Unfortunately, EA is pathetic, and will be sure to suboptimize DA4 like it has for any Bioware game released since DAO (2009).

If you plan on buying more DAI DLC, I recommend waiting a few months or so for a sale.  

I preferred Jaws of Hakkon over Trespasser, as Trespasser seemed like more of a dungeon crawl to me. Descent was OK, but it was also a dungeon crawl.

DAI isn't on Steam though, and Witcher III GOTY only costs 25 dollars/euros because it's on sale.

I couldn't agree more!