The Brita water pitcher and filtration system is one of the more economical water filtration products on the market. If you purchase the filters in a multi-pack they are very cheap, around $5 per filter.
I have the manual filter. These used to come with small stick-on calendars to help you remember when to change the filters. Since then they have stopped including these with the filters. I once received some gadget which was supposed to fit on the top of the filter to give me an idea of how much life the filter had left. It didn't work properly; if I'd paid attention to the indicator, I would have replace the filter every two weeks. I threw the little gadget out. Now I simply track the use of the filters by noting the date I installed them.
I recommend the Brita Pitcher water filtration system. However, you may wish to invest in the deluxe filter which features an electronic sensor which accurately measures how much water has passed through the filter. The indicator for the manual pitcher simply isn't very accurate.