Putting a countertop water filter system in your kitchen can supply you with pure water with zero effort. Tap water is fine if you like a strange taste and possible contaminants in your drinking water, but if you want water that tastes fresh and clean every time then an at-home filter is your best and most affordable choice.
What are normally known as countertop water filter systems literally sit on your counter top. These systems utilize a number of different filtration methods in a relatively small shell, which can seem amazing in comparison to what water filters used to be like (large and impossible to have in residences). There are several types of filtration methods these systems can use, most of which mainly utilize two to four filters to remove several different kinds of contaminants.
The bottom of the line filters are the kind that you can attach to your kitchen sink and the filtered pitchers. The tap filters do handle a great deal of contaminants very well but they remove minerals as well, which are more often than not good for your body. The problem with these kinds is that they can cost hundreds of dollars per year to replace their internal filters and they break very easily, especially if you run hot water through them. Filtered pitchers are even worse in that they only have one filter, which is made of carbon. These can only remove copper, lead, and mercury from your water. They do not remove harmful micro organisms.
A true countertop water filter system sits idly on your counter. You pour the water in and it goes through whatever that model's filtration method is and comes out clean. The higher end models utilize more than just filters -- some use ultraviolet light to kill off anything not caught in the filters, and some distill and steam as well as run it through filters to get absolutely everything out of the water. The distilling filtration systems can remove minerals, which could be a pro or a con depending on your needs.
Some high end models are capable of attaching directly to your water system to constantly provide clean water. These are convenient, but they are also hundreds of dollars more than the ones you manually pour water into.
Weigh your needs on which type of filtration system to invest in. Tap filters, which are the most common in households, are more expensive in the long run and can cost you upwards of $200 per year in replacements. A quality system will cost more up front but not cost so much in filters and repairs per year. Choose your countertop water filter system carefully and you will be happy with your water and the amount of money you spend to get it year after year.