Princess Daisy whom also seemed like a one-timer but started resurfacing in party games.
Daisy is Luigi's squeeze.
Anyways, I guess I can take a shot at a list of my own. Dunno if I can hit 10 or not, though.
Godzilla
You'd be surprised, but even a 50/80/100 meter tall mutant engine of destruction can get a lot of attention from the ladies. He certainly spars with Mothra, mother of two, often enough. And then there's Biollante, although that's somewhat incestuous. Nevertheless, a heat ray down the throat sure knocked her scales off. Both his girls got to dance with him in Godzilla Unleashed on the Wii.
Yoshi
You might not think on the surface that Yoshi puts a lot of effort into this. But if he can tell a male Birdo from a female Birdo (we all hope; it's in Camelot's hands) then that pretty much puts him ahead of the entire human race so far as attention to detail goes. You can't tell me he was born like that, the little green guy has to have a few secret romps in his catalogue. I'm sure of it.
Ike - Fire Emblem Path of Radiance/Radiant Dawn
Marcia flirts with him, Mia can't get enough of sparring with him, and Aimee would probably nail him with a bear trap if necessary. Then of course there's Elincia. For somebody who has shown no romantic interests whatsoever, Ike has quite a following
Phoenix Wright - Ace Attorney
Women of the Fey bloodline pretty much fall into the guy's lap, whether he wants them or not. No amount of Objections will stop that.
Sonic The Hedgehog
Amy pursues him relentlessly and he's adventured with other gals, not the least of which is Blaze (the only character outside of male hedgehogs to use emerald power in the newer games). He has quite a few other alternates outside of the gaming continuity as well, some of which made a cameo in Sonic Spinball (my personal vote goes to Sally).
MegaMan X
Alia may have been married to her work in X5, but from X6 on she seems to have her eyes on X quite a bit (one more in a long list of reasons I'm glad the series didn't end there). X even got a little flirting on the battlefield from Berkana. Then there's Nana competing for his attention next century. Despite this X isn't going to get any action unless he's blitzed, seeings how he's so hopelessly oblivious.
MegaMan Trigger
His adopted family (but not REALLY sister) Roll, and a pirate girl. Oh yeah, and the 2nd in command of paradise showed up naked even though there wasn't anything going on there (that we know...). Boy, he can sure pick 'em. As fun as it is to peek at someone who can slap you to death while they're changing/bathing, I think blowing their clothes off in a robot fight is much hotter.
Link
Four or five (wondering what "reward" Nabooru had in mind earlier...) girls drooling over him in OoT, 'nuff said.
Zero
Zero may not have matched Link's track record in a single game, but for a series with comparatively less emphasis on story and little dialogue between non-combatants, Zero's held up pretty darn well. Nailing 4 or more ladies (minimum: Iris, Layer, Ciel, and anonymous resistance chick) in a series of sidescrollers is pretty darn impressive.
Princess Peach
Who says the player has to be a man? Seriously, how many guys has Peach been cockteasing? Mario, Booster, and HIGH TECHNICAAAL chameleons are only the tip of the iceberg. She keeps Yoshi satisfied despite making him sleep on the roof. And of course, her biggest victim is the big man himself, Bowser. There's something to be said for having a giant snapper turtle who rules over every other creature in the world wrapped around your finger. Too bad the poor guy usually winds up getting dunked in lava whenever he gets turned on.