Whilst others might suggest other ISPs I can say that I've been with Eclipse for 9+ years with few, though not zero, issues. The issues I've had had tended to be with the accounts side of things rather than the actual broadband.
Eclipse are definitely one of the more expensive ISPs but I find that technically their broadband offering very reliable. I'm on Home Select with a 50GB download monthly allowance and get around 8Mb download and 0.9Mb upload speeds on a 21CN connection.
I have some reservations about their Customer Service of late, I hope that's a temporary thing rather than a sign of things to come. To be fair though I rarely have a real need to use CS, it's more the questions I sometimes ask that aren't responded to properly, sometimes not at all.
Despite that I'm not currently intending to change.