I've arrived into the question bank game pretty late, so if you're anything life I was, and haven't used question banks, here is a list of question banks I have come across:
Capsule: https://learn.capsule.ac.uk/profile
Capsule was created by a team at Brighton and Sussex Medical School and is now available to all medical students for free. It uses 'multi-step' questions, meaning there are a sequence of questions all linked to one case.
Pros: Free, Multi-step questions
Cons: Maybe more suited to BSMS curriculum than to other medical schools
Passmedicine: https://www.passmedicine.com
The classic, 'old faithful' question bank to many students, I had initially been put off using it due to the cost (£25 for 12 months)
Pastest: https://www.pastest.com/
Pastest is Passmedicine's mysterious cousin. Some people prefer it and it has questions for OSCEs and the SJT included.
BiteMedicine : https://app.bitemedicine.com/home
Bitemedicine also uses multi-step SBAs, which are useful for gaining knowledge on the different stages such as investigations and management.
Quesmed: https://quesmed.com/
Quesmed has a really comprehensive question bank with much shorter question stems.
BMJ OnExamination: https://www.onexamination.com