Blood Suckers by NetEnt is hands down THE best slot for wagering requirements. It has a 98% RTP which is insanely high compared to most slots. I’ve cleared countless bonuses with it. The low variance means you’ll get frequent small wins that keep your balance steady while you chip away at that 10k wagering. Just be patient and stick with it – the vampire theme might get old but your balance will thank you. If you get bored, Starburst and Diamond Dogs are also solid options with RTPs of 97% and 96.5% respectively. Whatever you do, AVOID high volatility games when wagering – they’ll eat your balance before you clear the requirements.