I think any comments by me about TestBash may be perceived as biased but I have blogs about them from before my start date of working for Ministry of Testing. I went to 4 before I became an employee and they were streets ahead of other conferences I attended at the time.
I would second Lee’s comments about https://testingconferences.org/, it’s a really useful site. One thing I also take into consideration when looking at conferences to attend is: Are the speaker’s expenses covered or is it completely pay to speak. Might seem silly from an attendees perspective but it’s a good way of checking that there’s the potential for a very diverse group of speakers. @maaret has a great spreadsheet on this!
In my limited experience of attending pay to speak conferences, the content has the potential to be quite sales pitchy which is totally fine if you’re looking to buy products but I wasn’t at the time.
One conference I don’t see on either of the links is SoftTest in Dublin which is not pay to speak, reasonably priced and had a really good line up last year. It was 2 tracks, one of talks and one for workshops that were first come first served.
I also like attending conferences where I can access the talks afterward. On that note, I enjoyed NTD 2018 because some talks I missed but I was able to catch the recordings afterward.
Leeds Testing Atelier is also a great one to keep an eye out for! A community run, multi-track conference and the tickets are free. Talks there are also recorded and shared afterward.