Tops are offered in laminated maple, hardboard or "shoptop" (Masonite ^®), "wood-on-wood", "pressed wood" and "flakeboard". Each has unique characteristics. And drawbacks. What is more, not all tops are the industry standard 1-3/4 in. thick. Some are 1-1/4 in. thick, which is okay for light duty  benches, but NOT okay for industrial benches. See above and See below.

Plastic Laminate is by far the most common surface for work-benches. It withstands abuse, 
maintains its laminated pattern, and is ideal for most applications, especially in high-tech and lab areas.  It is a high-pressure plastic laminated to a tight particle board core. It is resistant to many common  chemicals, except acids, and cleans well. It is available in a wide variety of patterns from solid white  to dark blue, although the most common and readily available colors are gray, platinum gray, gray linen,  white, and cool white. These tops are very attractive, presentable, and very durable. f you choose a  Plastic Laminate Top make sure its is *plastic laminate* and NOT "melamine" which is less  expensive, typically has a flake-board core, and which can be scratched off, and whose "wood grain"  appearance can be easily erased through rubbing or light abrasion. Plastic Laminate (laminated to a hard  particle-board core) is good for most applications, especially in lab areas and assembly rooms. If you are  using acids or acetones, however, get a "Chemsurf ®" or a chemical-resistant top which is resistant to acids and acetones
 

Laminated Maple Bench Tops are the strongest, the most durable, and the most expensive. It consists of 1-3/4 in.  maple strips electronically bonded for exceptional strength, and has a clear, durable lacquer finish. It is  solid wood, 1-3/4 in. thick. Laminated maple can warp, but it is extremely uncommon. Capacity rating is typically 3500 lbs. evenly distributed (and this is more a factor of leg capacity than the top).

Hardboard Bench Tops (shop-top, Masonite ®) are NOT a top made from deciduous (hardwood) trees, like maple.  It is a synthetic surface, 1/8 in. thick Duron®  that is hard and durable, but like any other top it can be  scratched, cut, and if glues are used, it can be "chunked-up" when pulled by a glued object, leaving pitted areas. It has good resistance to many common chemicals, but not acids or acetone. It is bonded to a  hard particle board core, and is edged on 5 sides (not the bottom). It is warp free and splinter-free. It has a  very smooth surface. 

Steel Bench Tops are an enduring standard for benches where abuse, weight, banging and cutting are anticipated.  Look for them in shipping rooms and hard assembly and repair areas where protection of the product  placed upon them in not a fundamental concern. It is typically 12 gauge channel formed for rigidity. It is solid but noisy. Pure functionality, it is invariably offered in shades of gray.

ESD Bench Tops are specifically manufactured to dissipate electrostatic discharge, and are extremely useful  as work surfaces for electronics components assembly. They are typically a white special laminate  although other colors are available as well. Remember that your ESD Top is worthless if you are not  seated on a conductive chair, or grounded to the bench top with a wrist-strap.
 

Wood-on-Wood Bench Tops are NOT a solid wood surface: it is a high-density sealed particle-board surface  laminated to another non-sealed particle board core. It is inexpensive and good for light applications of  a very general nature. It is susceptible to scratching, cutting, and marring.

Flake-Board Bench Tops: Forget it! Don't buy it. As its name implies, it is composed of flakes of wood derivatives,  and falls apart rather easily. It will not withstand abuse, hammering, cutting, or banging. It is the most  uneconomical "economical" top. Unless price is all you care about, do not consider these work  bench tops.

 A WORD ABOUT BENCH DRAWERS:

Here, too, there are typically two types available: Roller-Bearing Drawers, and Drawers. Both can be "stacked" under one another, but the Roller-Bearing Drawer, while more expensive because of the roller  bearings, is much easier to slide in and out, since it rolls on bearings. Friction Sliding Drawers are generally  of a lesser gauge steel, and simply slide steel over steel in moving in and out. Remember: you get what  you pay for!