Just want to filter out chlorine from tap water, can't stand the taste of it. I have looked at several under sink systems but don't know which one to buy. Need to stop buying bottled water.
Any carbon filter will get rid of the taste of chlorine.
Simplest: Brita or other pitcher. Or, if you don't mind the look/functionality, a filter that screws directly onto the kitchen faucet in place of the aerator. It will have a diverter valve so you can choose to have filtred water or not.
Cheapest long-term: Undersink OR countertop filter housing that uses standard "universal fit" 10" filter cartidges (these are actual;y a bit shorter than 10", closer to 9"). These cartridges are widely available (Lowes, HD or online etc), non-proprietary, and cheap. They come in a wide variety of filter media types (to get rid of silt, . Every 6 months or so cysts, lead, chlorine, etc). You just need a carbon filter element (granulated or block) to remove the chlorine, no need to spend a lot for a filter that does anything else. Every 6 months or so you'll need to unscrew the housing, remove and dispose of the the filter cartridge, clean the housing, base, and O-ring (with soapy water and a small bit of bleach), put the new filter in, and you are set to go for 6 more months. Filter changes take about 5 minutes and you'll need some space to get at the housing and remove it.
Most Convenient: Get an undersink model that uses "quarter-turn" filters. You just need one stage (not a unit with 2-3 filters). With these, you don't need to clean out a housing or do anything complicated. Every 6 months or so you turn off the attached valve,turn the filter housing 90 degrees and it pops out, put the new housing and filter in place with a quarter turn, and you are back in business for 6 months. It takes about 30 seconds to change the filter. The filters are more expensive than the universal fit elements (above), and if the manufacturer you choose quits making them, then you'll need to buy everything from scratch again. But these are still more convenient, cheaper and much more environmentally friendly than bottled water.
If you aren't willing to remember and actually change the filters every 6 months, then stick with bottled water. Once you remove the chlorine from the water (with the filter), the water and filter will begin to host some microbes. Things can get nasty in there if the filter maintenance isn't regular.