Bann Teagan, Cullen, Ser Gilmore, and Jowan are all great possibilities, and that's in order of preference. The first three are hands down the ones I would want most. I am SO happy to read this thread and see that I'm not alone! Seriously, this is making my frigging day, big time. I love all of you!
Bann Teagan already has flirtations in place; all that would be missing is a little bit of tentative flirting at the Landsmeet and a kissing scene at the very end of the game right before a happy epilogue. He's a perfect choice because he's handsome, incredibly well-voiced, and such an obviously good man. Noble, but not political, so he wouldn't go dumping you because you're an elf or dwarf like somebody else who shall remain nameless. Bann Teagan would be the real fairy tale ending. I actually held out on getting it on with Alistair throughout most of my playthrough because I kept half-hoping that Teagan would be available.
I had entertained the thought of him having slept with the buck-toothed wonder, but dismissed it because (a) as reprehensible a person as she already is in many ways, sleeping with Teagan would push her over the edge into outright villain territory and I believe her love for Eamon (who is pretty hot for an old guy) seemed sincere, (

Teagan's emotional connection to Connor is already established as his uncle with whom he goes hunting, © I don't believe Teagan would do something like that to a brother he loves so much, (d) the anim guys are good enough that if they were I believe she would have stroked his arm or something intimate; the kind of thing people do without thinking when they've been lovers, (e) I sensed no unspoken guilt hanging in the air and saw no guilty longing looks when Eamon awoke, and (f) it would all just be so SOAP OPERA. So no. A billion times no. That would be so lame.
Cullen... the whole tortured star-crossed lovers vibe a female mage has with him ripped me up into little pieces. He's just so gentle and kind-hearted when you first meet him, whether you're male or female, but if you're a female then he is shy and adorable--all that
stammering! (Not to mention how he literally RUNS AWAY if you want to talk to him privately! Aww... so cute... so funny...) He
really tugged at my tender side. He was so guilty about being attracted to you, and had such an opinion flip about mages after the whole Circle Tower thing... actually, Cullen is on par with Bann Teagan in my book when it comes down to it. I just wanted to show him that mages could heal and soothe as well, give him some peace and help him get over the nightmare he went through. I wished so hard that you could be nicer to him! I have such a soft spot for the kind of guy who has feelings for you but can't admit them.
Two such small parts, but great actors, great facial expressions, great appearances (Cullen is handsome in an appealingly odd way; Teagan is just plain drool-worthy) and the writing was very skillful in my opinion. Come to think of it, Teagan and Cullen both do this little faint squinty thing with one eye when they're feeling embarrassed; it's incredibly endearing... well done.
Ser Gilmore... *swoon* I couldn't believe you could only shag that silly boy Dairren. Gilmore was so strong of character, and so gorgeous. Why not him? I would love to find out that he survived. Hell, maybe Arl Howe knew his position, took him hostage to try to coax the location of your noble PC out of him, and you find him nailed down in the torture chamber all sweaty and desperate and full of gratitude and--okay, I'll stop before I either frighten or excite someone.

Jowan is whiny, but a deep character and certainly interesting, and not bad to look at. Daveth is hot, and earnest, if a bit cheesy in personality, but he's braver than Jory for sure and I liked him--then again, he dies, so that's definitely not my first choice anyway.
Who I would NOT like to see are Loghain (he's hot with Morrigan, but he's too old and it's inappropriate/twisted beyond words to screw the guy who murdered your mentor and possibly got your family killed, and in my heart he's always Rowan's anyway) and Sir Greagoir (he's like 65 and he may like Irving for all we know. If not, he might give companion Wynne a spin.) Cailan... actually, why not? He's quite attractive, and it's nice to think of the poor naive kid getting laid before the battle. Who knows if that frigid priss Anora ever had any fun with him. Duncan I could also see, he's not to my tastes (I'd see him as like a cool uncle) but he's dashing and badass and he dies, so it's the same thing as with Cailan and Daveth--one for the road, poor doomed guy.
On the female side, Shianni was great, although of course not if you're a City Elf, which makes it all but impossible. Kaitlyn from Redcliffe was also really nice, though I think that Bella would be a more natural choice. Gheyna's pretty, but you couldn't do Cammen on the flipside because he is such a mopey little kid, he acts like he's 14, which would feel gross (plus as Tamyn says, he's not even cute.) Dagny would make an AWESOME choice; she's the cutest thing! I adored her in a friendly way, and she'd make a good love interest for some of my characters, I would say. Lady of the Forest is elegant and lovely, but storywise it totally wouldn't work.
And this might sound crazy, but I kinda wished you could spend an exorbitant sum of money on buying one of the brothel prostitutes so they wouldn't have to put on the red light anymore. I mean, you could seriously make a great mod out of something like that. I'd love a romance with a jaded male elven prostitute. All the fun of trying to redeem Zevran without the weird coloring and the nonexistent conscience! Wynne would be so happy. (Wynne in the game, I mean. Although, me too.)
It is so not fair that you can't kiss any male NPCs like the guys can Bella and so forth. I'm bummed about that.
Call me stupid, or lame, or whatever, but if somebody made a pack of like 5 each non-companion romance options of both genders (10 in all), then if it was decent and they were the NPCs I was looking for, I would seriously pay like $40 to get my little hands on DLC like that. I'd spend it without even thinking if it was good. If there were 6, 3 of each gender, I'd still fork over like $20. I'm that fond of options and happy endings. It would be SO worth it.
To hell with yet another location mod you can teleport to and run around and kill things in like you can everywhere else, give me Valentine's Day DLC!