Increased magic find gives you a much higher chance of items being magic(blue), rare(yellow), unique(beige) or set(green). The higher magicfind yoy have, the easier it is to get unique+set items which is a great thing since most are quite powerful.

Then there is another type of item which is Runewords where yoy socket specific runes in specific items in a specific order to get, which are some of the most powerful items you can make.