In order of appearance:
Aveline - Friend
Varric - Friend as well, though... after I've experienced the not-so-neutral ranting he does if siding with Merrydeath eventually, I'm tempted to see how he does "in red".
Merrill - Friend. She's my Hawke's "canon" romance and the only romance in a Bioware game I'd say is a go-to. I did her rivalry romance once, but carefully made sure to show my Hawke's stances (like destroying Tarohne's books) instead of lecturing and avoided falling into abusive territory / harping about "OMG, evul blodd magick" at every turn. Needless to say that I was not fond on how DAI handles Hawke, ranting about Blood magic at every opportunity.
Anders - Friend. Though I headcanon that it is pretty strained and turns into some sort of "semi-rivalry" towards the end when it comes to disagreement about methods. If I got a Hawke who's really annoyed by him, Anders is usually made to leave the party in the aftermath of "Dissent".
Fenris - Quick and easy rivalry, usually. I do have a playthrough with him being friend-romance (Bloodmage Hawke for extra irony), but that degree of friendship was achieved by carefully contolling his presence in certain situations, as the Hawke in question still did not feel like agreeing with his anti-magic rants.
Isabela - Usually went for blue, as she takes purple Hawke well. On the other hand, I'm constantly torn to be less nice due to her rather... exploitive (?) shenanigans. Probably have to try red some day.
Sebastian - Rivalry. Only had him in one playthrough, but mage!Hawke did not feel like agreeing with his attitudes much. Or his passive-aggressive preaching.
Also, on a gameplay-dependent note, his blue bonus passive is said to be glitched, and unlike Isabela's, it apparently never got fixed.