Here's a couple of sites for anyone who is interested in visual novels.
Renai.us the Ren'Ai archive is a site that holds a collection of free English-only visual novels. Most of them are made by novices using the renpy engine. Browse at your own leisure, there isn't anything outstanding on the site but it'll give you a taste for VNs if you've never touched them.
insani.org Insani hosts Japanese games that have been translated/partially translated into English. There are a few fully translated games on there, some are only demos.
http://vndb.org/ the visual novel database is probably your best bet if you're looking for any visual novel. The site is an archive for many, many visual novels. It's insanely useful for anyone looking for anything new or old. Even if the VN you're looking for is in Japanese only, it will usually give you a link to a working English patch. This is only an archive and as such you will not be able to download or buy any visual novels from here, though it will link you to the developer's site and the site that has the visual novel.
That isn't every site, but most of my VNs come from a mix of those, or JASTUSA, J-List, etc.
It's best to browse vndb.com and just see what catches your eye. Here's a list of the top ranking visual novels on the site, probably best to start from there and work your way down.
I haven't played a visual novel in a while now but the last one I finished was Kara no Shoujo and I loved it. A thriller/detective VN. It's surprisingly unforgiving too, you can fuck up very easily and be expected to replay a good 1-2hrs of reading if you haven't picked the right choices, or missed out on clues, etc. I only finished two endings before I got frustrated so then I had to use a walkthrough for the rest.