So I've been on a Steve/Tony reading binge for the past five months and went ahead and posted recs because I like having them in one place to read later. There's over 200 fics in this, and they're divided into categories (because as much as I love MCU, I absolutely love fics from other universes such as Marvel 616, Ultimates, Avengers Assemble, etc. Steve/Tony is awesome in every fandom ever, and there are so many great fics in this fandom, it's mind-boggling. (Thank you writers!) <3
Anyways, here's the link.
MCU Phase Two (AoU/IM3/CATWS) *
MCU Phase One *
Alternate Universe (Multiverse) *
Marvel 616/Ultimates/MA:A/Cartoons/Other