Not to derail this, but some of my least favorite episodes of Trek are the "sexy" ones.
Star Trek doesn't exactly have a stellar record of doing "sexy" right. (ENT's decontamination scenes being the most obvious offenders, but I think it applies to the other series as well.)
I'm having trouble thinking of an episode of Voyager that I genuinely felt was sexy. All the moments that could have legitimately been erotic felt so awkward. Like Paris and B'elana rolling around on the ground when she was in Pon Farr. And Seven was dressed sexily but Jeri Ryan was very effective in acting in non-sexy mannerisms. The only character who could have pulled off sexy was Janeway and she was never in sexy situations. I suppose if Kes had stayed and had a courting period with Paris that could have been sexy. I guess, the way Seven was dressed in Killing Game was rather attractive.
Voyager, season 7 Workforce II the scene AFTER Janeway burns Jaffen's dinner and she brings him coffee before curling up in his lap.
http://www.youtube.com/watch?v=j1OFvyxfBhk
[yt]http://www.youtube.com/watch?v=j1OFvyxfBhk[/yt]
Voyager, season 5 Timeless, Janeway & Chakotay in her quarter's discussing the pros & cons of using the slipstream drive to get home.
Janeway is the only one who can make such a discussion sound sexy. (Sorry, can't find it on youtube any longer.)
Let me set the scene.
Its Janeway's quarters, the lights have been dimmed, the table is set for two with a floral centerpiece. They are both still in uniform.

JANEWAY: Come in. Commander, I hope you've got an appetite.
CHAKOTAY: Famished, but I assumed you called me here to talk about the Slipstream flight.
JANEWAY: No reason to cancel our dinner plans. I've programmed a dish my grandmother used to make back on Earth. Vegetable biryani.
CHAKOTAY: Sounds delicious. I didn't know you could cook. JANEWAY: Normally, I draw the line at a pot of coffee, but tonight is a special occasion.
CHAKOTAY: Oh?
JANEWAY: Our last night in the Delta Quadrant. I'd say that's special enough.
CHAKOTAY: You've made your decision.
JANEWAY: We launch tomorrow at oh eight hundred. You and Harry will take the Delta Flyer. Voyager will be right behind you.
CHAKOTAY: The crew will be pleased.
JANEWAY: You can give them the news yourself, after dessert. What about you, Chakotay? What do you think about my decision?
CHAKOTAY: I've analyzed Harry's flight plan. The theory is sound, but there are just too many variables. If something goes wrong in that slipstream...
JANEWAY: It could be our only chance to use the Quantum Drive.
CHAKOTAY: True, but if you showed this data to any Starfleet engineer they'd think we were out of our minds. We can find another way home. We've waited this long.
JANEWAY: Long enough, we've waited long enough. I know it's a risk, probably our biggest one yet but I'm willing to take it. Are you with me?

CHAKOTAY: Always.

(Then she stands up, walks around the table to stand next to him before resting her hand on his shoulder.)
JANEWAY: Speaking of risks. Are you ready to try some home cooking?
CHAKOTAY: I'll alert Sickbay.
