Honestly, I tend to forget Solas and Blackwall are even around. Cullen, I can't forget because he's at the wartable, but I never found him interesting -- I already knew who he was from previous games and I didn't like that person. I'm also not a fan of characters that are too angsty. As soon as someone starts saying, "I'm no good for you" or "we shouldn't be together," it's an automatic drop.
My favorite romances are Josephine and Dorian. Josephine was sweet, simple and very fairytale. That worked for my first Inquisitor. Dorian had a lot of realism that I appreciated. Cassandra, I haven't romanced yet, but when I made a male inquisitor for Dorian, it was a massive struggle to not flirt with her. I really enjoy her as a character and she's definitely someone I have no problem devoting hours of gameplay for. The only other people I'm interested in are Bull and Sera.
But, all and all, what it comes down to is different preferences.