What's your budget?
Palmolive sticks are available in Tesco and Asda for 50p and are genuinely great, Arko is a "must try" that is practically impossible to mess up, but has a scent that divides opinion.
Mitchell's Wool Fat is another old favourite that costs around a fiver, I think. The Kent shaving soap is the same, just rebranded, and is available from John Lewis.
Going up the budgets, I can highly recommend DR Harris soaps and Wickham Soap Company (a member here that makes, possibly, the best soap I've tried) but both of these are in the £15 range - well worth it in my opinion.
I see you're in Dundee - go down to The Gentleman's Groom Room and have a check of the soaps yourself. I've yet to go, but am toying with the idea of a trip in next week at some point.