My preferred pairings are Tony/Steve, Tony/Pepper/Steve, Clint/Steve, Peggy/Steve or Sam/Steve, but I can't think of any Steve pairing I wouldn't read.
The hardest part, though, is in the details, isn't it?
While I think it's awesome for fans of certain popular pairings that they're so popular that they even end up in the background of everything else, it's really hard to work around some of them in this particular search. So I'd really like to know if anyone has any recs that don't also include Thor/Loki, Natasha/Pepper, Tony/Bruce, or Clint/Coulson (unless it's Clint/Natasha/Coulson) anywhere in the fic. Especially Thor/Loki or Clint/Coulson.
Any level of sexual content is acceptable, from none at all to explicit. Any length. Any overall genre.
I love that Steve is able to lead everyone on the field, but I just really like Steve being a bit more submissive/uncertain/etc to his romantic/sexual partner off the field. (no, uh... crap, I don't know the right terms for everything, but no watersports, scat, or any similar kinks)
(also, I'm not sure I tagged this as well as I could have. I wasn't sure what all actually applied and most of what I'd actually use isn't in the list.)