Let's start with what you don't want: another pair of square toe shoes. These were popular for a long while and are still around. A lot of them are bulky and don't go well with a well cut suit. Some can be slim enough to compliment a suit nicely. The ones to avoid are the widely squared toe shoes with thick, clunky soles.
What is in style now, and will always be in style because they're classic, are a nice pair of round
toe lace up oxfords. Stick with these and you can't go wrong. Wingtip, cap toe, plain toe, etc. Keep them clean and polished, use shoe trees, and they'll serve you for a long time. If you have the means, treat yourself to leather soled shoes, especially if you don't have any yet. They wear beautifully, last a long time, and you can have them resoled when the soles get a bit tired and it breathes new life into them for several more years. Rubber soles have their place (if you're on your feet a lot, need the traction, are in inclement weather a lot). 
Loafers and slip-ons are also great. Some can be a bit casual for a suit (like the driving shoes pictured below) but they can be dressed up with jeans and a blazer or down with jeans and a T shirt. The loafers pictured are definitely suit friendly, or can be worn with jeans.
One final note: unless you're going to pair them with a black suit, try wearing brown shoes with most suit colors. There are lots of great shades to choose from, and they go best with grey, blue, and khaki suits. Apply these tips the next time you buy a pair of shoes and you'll come away with slim, classic shoes that are also modern and in style. Take care of them and they'll help you look great for years to come.
