Wow... too many to count. Some of the top ones are, of course, the genius Nora Roberts. Others are Jude Devarux, Kate Martin, Jane Ann Krentz, Amanda Quick, and tons more. Many of them also have aliases that lean towards a different end of the spectrum than their main works. The real question isn't "how many are there?" because, geez, that list gives me a headache, but "which ones are really good?" As I've gotten older, my taste has distinguished itself, and let me tell you, there are some really crappy romance novels out there. If you find a good author, stick with her, because if you like the style, it often doesn't change, and romance novelists are kinda infamous for pumping out TONS of books. My personal favorite is Nora Roberts. She's a modern romance novelist, who has recently been adding sprinkles of magic and murder to her books. Other common time periods are Medevial, Regency/ Victorian England, Old West, and modern. While some of the older ones can be cheesy, modern novels can seem cynical, and, well, stupid. It takes a while to carve a decent set out of a lot of the crap that floats around, but it can be done.