This can be a tough question that is usually answered by asking additional questions. Be careful when shopping if you run into a sales guy that gives you a specific piece of equipment right away without asking any questions; he or she may not have your best interests at heart. General questions usually get general answers. So, please do some homework on the equipment your looking for. Another way to get good information is to talk to salespeople that are knowledgeable - So you may have to try a few places. 

Here are a few questions that should be asked of you:What kind of space do you have available?

• What is an activity you like to do?
• What are your fitness goals? (This piece of equipment may be supplementing your workouts, or you may be training for a marathon. All this will play a part in finding the right piece of equipment)
• Do you have any health or physical limitation to using equipment? 
• What are your expectations from this piece of equipment?
• How many users will there be using this piece of equipment?

Depending on how you answer these questions additional questions should be triggered in the salesman's head- many, many more questions should be asked to help you find the right piece of fitness equipment. This will help narrow down every piece of equipment into categories and sub categories. The three most popular categories for cardio workouts are: Treadmills, Ellipticals, and Exercise Bikes. Usually everyone finds what they're looking for in these three categories. On the other hand there is strength equipment that usually falls into two categories; home gyms and free weights. This question on how to find the right piece of fitness equipment can drag out, but the best way to find the answer is by asking a lot of questions and find someone knowledgeable to help you.