I currently am with Bigpipe since at the time it seemed to be the best choice for bringin my own modem and static IP. Their DNS changes don't bother me since I don't use their DNS servers anyway.

But out of interest I thought I would check out Spark since I use Spark in my apartment.  Unfortunately their online address checker says UNPLAN Broadband is unavailable which doesn't fill me with confidence given I am on unlimited fibre with BP at the moment. I also checked my neighbour who has fibre and got the same result. 

Just might stay with BP until they stop service!