I signed up with Nectr. Their rates are the cheapest for my area. I didn't have to pay any additional charges when signing up to their Nectr Clean plan and they don't have any credit card charges, while some other providers wanted to charges $42 for an initial meter read under Endeavour network.
Transfer from AGL (Provider of previous tenant) was seamless and took 3 days
This offer started on 25 May 2020 and ends on 30 November 2020 (Offer Period).
Guaranteed sign up credit: $100 credit* on your 2nd bill
They have a different offer under Ausgrid Network (NSW):
https://www.ozbargain.com.au/node/533325
Update: Ausgrid $200 offer expired. Now Ausgrid is $100 credit as other providers in this post.
On the Government Energy Made Easy comparison site, Nectr show as being the cheapest when doing a comparison search (That is they come up at the top of the list, and as you scroll down, the plans go up in price.
https://www.energymadeeasy.gov.au/
The kw/h price being shown on this site does not show correctly (even when adjusting for GST) - but that is a reflection of the website (and not Nectr).