Laser vs Inkjet
Most people prefer to use laser as opposed to inkjet unless they want color output, or larger than letter/legal size, for the following reasons:
Laser is faster
Laser is not as dependent on paper properties for quality output. Special inkjet paper can cost a lot of money, whereas lasers will usually get very good results with almost any common photocopier paper.
Ink from inkjets can be soaked up by the paper and cause the paper to wrinkle. Also, ink can smear before it dries. Laser toner is (usually) bonded to the paper before the page is expelled from the printer.
Ink cartridges for inkjets cost more per page of output than toner cartridges for lasers, although the initial purchase price of lasers are usually higher then that of an inkjet. During the life of the two, the laser should ultimately have the lower cost per page, both in terms of price and hassle.
Inkjets have nozzles which spray the ink onto the paper. These nozzles can become clogged and cause blank lines between your output (also known as banding.) Some inkjets have cleaning cycles to rectify the problem when it occurs, others insist that you replace the ink cartridge (or monkey around with cleaning solvents and odd procedures for unclogging.)
For printing graphics intensive work a laser can be limited by the amount of memory you have installed in the printer. If a page has a lot of graphics information the laser may not be able to print it (unless you spend more money on memory.) Inkjets do not suffer from this problem.
So, when deciding whether to buy a laser printer or an inkjet, keep these factors in mind.