What are the best pay as you go sims that you can buy from just about anywhere to call Norway & Denmark?

Probably Lyca Mobile, their international rates are generally very good.

Denmark landlines 6p
Norway landlines 7p

http://www.lycamobile.co.uk/en/internationalrates

Three have some short code options for cheap calls. Can be handy. If you don't mind having to do the short code before the call.

Eg: http://www.uk-justdial.com/jd/pages/...re%20to%20call

Denmark 3p
Norway 3p

Depending on how much you use (I call denmark 1-1.5 hrs a day on average) you could set up a skype subscription (c.£13 per quarter) which give virtually unlimited calls to any eu landline.

If you call from a pc no extra cost.

If you want to use a phone, set up a skype to go number (a uk number which maps to you danish/norwegian number), and then you can call from any uk phone only paying local call rate. e.g. you call say 0141 xxx yyyy and you are routed to say (0045 bbbb dddd)

You can call this number on any landline or mobile, and can use any inclusive minutes.

As I have a landline with unlimited calls anyway, I only pay £1 per week for c. 10 hrs to Denmark i.e. 6 minutes per 1p.

It doesn't take much calling before above route is much cheaper.