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):
Update: Ausgrid $200 offer expired. Now Ausgrid is $100 credit as other providers in this post.