Please, before you add/vote on this list, take into consideration the following requirements:

The romantic relationship must involve main male characters only.

Nominate first book only, or first published book for the ones that aren't designated as part of a series, but you know for sure that they're related to one another.

There must be at least two books in the series (if you know there's a planned sequel don't add it, unless the continuation is finished, and its release date was announced).

Don't add series based on stand-alone books (no sharing of common themes, characters, or settings).

You can add besides officially published titles, also unpublished ones (online completed works), preferably novel length.