Octopus Energy have been recommend by Which? consumer magazine for many years.
Several other supplier such as Good Energy use Octopus' Kraken IT system but in case of Good Energy and Coop also customers service. But have different energy mix of sources they purcahse energy from, but both support renewables. Good Energy remove meters and cap gas supplies for free, like Octopus.
Octopus like many supplier have refferal scheme which is annoying spammed onto various consumer energy forums, despite Octopus Energy's rules on their use:
"7.5.6 We have reason to believe you are sending or advertising your Personalised Link to people who are not known to you or if you are in any way trying to benefit from our referral scheme on a commercial basis rather than for personal use. We may review any account we think might be "taking the mickey" particularly if we receive complaints from other customers, or if you have referred over 10 people in any 12 month period and we reserve the right to deactivate your Personalised Link or move you to a different scheme."
Related links including other suppliers using Octopus Kraken Tech and also electricification of heat below.
If you use Facebook then many Octopus groups some dedicated to specific tarrifs. Also Octopus Energy customers have shared experiances on Energy GB Facebook group.