Playtech is arguably the most successful online bingo software provider of them all. They constantly win all of the top awards for bingo software, and the brands on their network are almost always big high street names with considerable marketing power.
Over many years they have built up a robust bingo product with many fun and unique variations on bingo that add more to the experience than just the 90 and 75 ball that you'll find elsewhere. The most popular of which are the Deal and No Deal Bingo series and the Rainbow Riches Bingo game. There are loads of them and many individual brands have worked with Playtech to built bespoke games just for them, such as The Voice UK Bingo over at Buzz.
The only things that let Playtech down in my opinion are that the lobbies for all these sites look very samey, especially on mobile. There is a lot to do in the games and this sometimes makes the experience more complicated than it needs to be. If they could simplify things more I think it would make a big difference.
Overall, it is the biggest network around and so rooms are always full with big jackpots. I recommend pretty much every brand that uses Playtech, you can't really go wrong.