If you are looking for a reliable dating website or a website that can just hook you up for some casual sex, you should check out instashag.com, especially if you are from the UK as most of the members come from that area.
Even if the website has quite a lot of registered members, you should be very careful about fake profiles that lurk on the site. The registration to the website is completely free, and you can enter the area you live in, your sexual preference, and all other info for free. However, in order to actually send messages or chat with other members, you will have to upgrade to the golden membership. This membership is available for a couple of subscription choices, and to be honest, it is a must buy if you want to do anything on the website.