There are literally hundreds of bingo sites on the internet, some similar and some very different from one another. Finding the right one for you is a little like finding the right car insurance company. There is no one single company that is better than all the others, it's a matter of finding the one that provides the right services to meet your particular needs and desires at the best possible price- or in the case of online bingo, the one that is most likely to give you the most fun and let you take home the best winnings.
The first thing to do is make sure that any bingo sites you play on are legitimate. If they are registered in the UK (although they won't necessarily have a .co.uk at the end of their name) they should state clearly that they are subject to the usual rules and regulations regarding online gaming in this country. If registered elsewhere, there should still be some indication that the site acknowledges a set of national laws and regulations.
Look for additional certification from GamCare and GambleAware.co.uk. Any online bingo website that has either of these icons should be well run and meet ethical standards. Whilst neither are a solid gold guarantee that a site is a good one, they are a good start.
Many bingo sites offer additional services like forums and chat. These may not help your bingo game but they are fun to try- one of the biggest reasons to play in a bingo hall has always been the social aspect, meeting new friends an chatting with old ones. There is no reason to give that up if you decide to play online. Have a look around the website and see what kind of social opportunities there are before signing up.