Have you ever wondered what a doubled edged safety razor is?
(often called the DE safety razor)

Just know that it's probably what you think of when you think of your Grandad shaving.

Are modern cartridge razors better? No.
Actually, their shave is markedly worse

If you're looking for a great gift for him, or her 
(the razors with teeth on one side are great for shaving legs),
then a top-of-the-line DE Safety Razor is the answer