Suit patterns come in many different varieties than just the standard solid colors. There's a lot more you can find for your wardrobe that can spice things up.
The solid pattern suit is the most popular, and the one that most men know. Its a good choice for a first time buyer. Its conservative enough and works with enough shirt and tie combinations to mix in with most men's style statements.
The pinstripe is a little more flashy. For years it was popular with wall street bankers but its started to get more popular in the mainstream. Most of the time its a solid dark color with lighter thin vertical stripes. Its a good choice for shorter men.
The plaid suit may give off some ideas of a professor, but with Mad Men featuring it, its becoming more popular.
A check pattern is a design with both thin vertical and horizontal stripes. Its a more casual look than pinstripes or a solid look.
Glen Check is much like the check design but it is usually with one color only. Its a casual style as well. Its more popular in Scotland and the UK.
The windowpane suit is similar to the checkered look but the stripes are farther apart. This is more of an old school 70s look and can be tough to find. It may work as part of a vintage look though.
Herringbone - Its usually a subtle zigzag pattern. A little more edgy than a solid.
Houndstooth is also a more of a jagged and uneven pattern. Its much more commonly found in jackets. Houndstooth coats are very popular.
Nailhead is a less common design where there is a solid background color, with lighter colored dots of fabric sprinkled throughout. It can be a good substitute for either a striped or solid suit and is suitable for many occassions.
You'll find many suitmakers carry the solid and pinstripe designs. Check and plaid can be somewhat more difficult to find ready to wear. For specific designs, you may need to look into a made-to-measure or custom suit setup.