Reviving this topic because I read several interesting books recently and I thought I should share, if anyone cares:
Adrien English series by Josh Lanyon - I've read two volumes and so far I like it a lot. Interesting plot, not annoying main character and realistic relationship.
Tony Foster books by Tanya Huff - a sequel to the Vicki Nelson series, but I think it can be read separately. Funny, interesting and different than other books in this genre.
Wicked Gentlemen by Ginn Hale - not as good as the previous two, but still worth reading, especially if you liked "Swordspoint" by Ellen Kushner (I did)
Infected series by Andrea Speed - I didn't expect it to be good, but it was. A quite long series, but reads very quickly. Realistic characters.
Tainted series by Sam C. Leonhard - didn't love it, but didn't hate it either. The main character is sometimes a little annoying and the plot doesn't run very smoothly, but it's still worth trying.