Been signed up at Single Bet Calculator since the spring, mostly late at night on the sofa, so take this for what it's worth. Found it through a Reddit thread, wasn't an ad.
The game selection is genuinely huge — a bit over 3,500 games if the counter is honest. Play'n GO takes up most of the space, so Book of Dead and the rest of the greatest hits all show up. Personally I mainly play Big Time Gaming megaways out of pure habit. One gripe — searching for a specific slot at Single Bet Calculator is more faff than it should be, I usually just scroll and hope.
The live dealer bit is powered by Evolution, so you know what you're getting. Actual dealers, no lag issues on my broadband, and Crazy Time and Lightning Roulette is where I lose most of my money, honestly. Should mention the British tables are properly staffed from about 6pm onwards. If you want to compare the current terms have a look over on single calculator bet since the offers shift about.
Bonus-wise at Single Bet Calculator was a 100% match to ?150 with 50 spins. Wagering is 35x which is standard-ish. They also ran a small no deposit thing when I registered. Min deposit is ?10, sign-up took me maybe five minutes, verification took about 24 hours.
Withdrawals have been fine. Debit card are the slow ones, Skrill and Neteller hit in a few hours, and crypto clears fastest. Took out about ?250 recently and it landed early. Single Bet Calculator's support took ten minutes once, three another time — copy-paste at first but fine after. Properly licensed for UK players, which matters more than the bonus size. No standalone app, which is mildly annoying but the site works fine.