Seen this deal for a new S8 with 10GB of data on EE for £37.99 per month. Very good for a deal with nothing to pay upfront. If it tracks you can get cash back from Topcashback for £36.75 so that's basically your first month free.
Can't see a better deal online for an S8 with nothing to pay upfront and all the data you need. I think there will probably be some good deals around for Prime Day too!