Any NPC's you wish you could have romanced?

I'm of the opposite opinion. I similarly find the virginal fangirl routine to be banal, having seen it in male oriented media so often, but in Tali's case it's at least excusable to an extent. She tries to get intimate with someone and runs the risk of very bad things happening to her health. Combine that with the fact that she isn't that old (hell, I know 24 year old virgins IRL who don't have any of the associated risks), and that they didn't really emphasize it so much as mention it in passing, and I can at least stomach the logic, even if the execution is a bit eye rolling (though I suspect Tali's romance arc was aimed primarily at her typically teenage to young adult fanbase, whom, lets be honest, a significant number of whom are probably virgins). Further, the whole "fangirl" thing she gets over rather quickly if turned down, and simply moves onto other things (namely Garrus), showing a bit of emotional maturity.

Liara is a little less explicable to me. She's 106 years old (more than 4 times Tali's age in ME2), has no physical aliments, and is from a culture that seems to be pretty open in regards to sex, so would presumably have to have some crippling social anxiety disorder or something in order to have never had a sexual relationship. Yet, she's pretty aggressively trying to get in Shep's pants from like the 2nd conversation she has with them, talking all about asari reproduction(wat?). It's pure juvenile Orion girl fantasy, as if she was just waiting for you and you alone to finally come into her life after 10 and a half decades, and if rejected never moves on to anything else within the course of the games' narrative despite opportunities, like say Feron. (Though, in fariness, this isn't just Liara. Hardly any of the ME LI's seem to have a love life outside the player character, Ashley, Jacob[LOL] and Garrus/Tali being the only notable exceptions OTOH).

Of course, both of them are less cringeworthy and far more enjoyable in installments subsequent to them first being made options, so good on Biower for growing up a bit past the "who doesn't want a blue/purple spacebabe" boys club attitude.

I maintain that Xen would have been more fun than Tali, and Aria more fun than Liara. 

Khalisah Al-Jilani

James \o/

Chakwas, Kasumi and either Emily Wong or Khalisah al-Jilani. I strongly feel that either Wong or al-Jilani should have been the reporter onboard in 3. It would be best for al-Jilani, didn't like each other the first 2 games then at the end getting over the differences and growing close. There could have been a lot of potential there for a fascinating romance.

Aria. I have this soft spot for her. Can't resist.

Joker, Legion, and Mordin.

Joker: In another life, maybe.
Mordin: If wanted to try human, would try you. (Translation: Not interested.)
Legion: Reaching consensus.

I had high hopes Joker would be romanceable in ME3. Even had a single FemShep ready to go just in case. Alas.

EDI, for obvious reasons, and with my femshep Carolina Shepard.

Bailey, Normandy Requisitions Officer (think of the sweet deals you'd get!), Etarn Tiron (especially if you killed the original Council), Kenn, Aria, Feron, the Shadow Broker, as a means of distracting him from helping Feron and Liara escape, Harbinger (in Collector body only)

Aria motherfucking T'loak of course

Kasumi

Mordin, Javik... and Legion. Also, Techno-Turian.