QE2, Fred Olsen, Saga are some that have cabins for single cruisers. Kind regard.
Most do, but at a price. Fred Olsen sometimes have a good offer for single travellers, but the best I have had was a wonderful 7 night cruise to Greek Islands and Turkey with no single supplement April, May, June, September and October. The ship was The Blue Monarch, Monarch Classic Cruises, and we had a wonderful time in single cabins for £599 which included flights to Athens transfers to Piraeus to join the ship. Food was excellent and a very international mix of passengers. English is the main language on the ship and I thoroughly recommend it. The advance brochure for next year can be viewed on www.monarchclassiccruises or www.mcc.com.