I just want to clear up some confusing statements that have been made, and try to clairfy your question.
Hope this helps!
First of all, a townhome is a STYLE - it is not a form of ownership. Single famiy homes are usually conveyed with deeds that are called "fee simple". That is one form of ownership. With another form of ownership, a condominium, you are given a deed to the property, which may include a few feet around the perimeter (if it is a townhouse style) - you OWN THAT UNIT, regardless of the style. In the 3rd type of ownership, a cooperative form of ownership, you are not given a deed to the property itself, but you are buying a PERCENTAGE of the building or complex.
A "condo" may be in the STYLE of a townhome (ie - free-standing, connected or multi-floors) or, it may be on one level, an apartment style, in a high rise building. Along the same lines, a cooperative may also be a townhouse style, or in a high rise building. All these terms are confusing to a lot of people!
When purchasing a condominium, you generally have the freedom to sell it to anyone you want. In a cooperative form of ownership, you will need "board approval" or permission, as you don't really own your own unit. This can add time and frustration to the process, Condominiums are easier to sell, because they are less restrictive. Both forms of ownership include monthly fees covering the common areas, although with a coop, the fee usually includes your portion of the property taxes. You are responsible for paying your own property taxes with a condo. There are bylaws, rules and regualtions for living in any of these types of communities. Associations and condo or coop boards come in all shapes and sizes...some are lenient, some restrictive. Discuss this with your realtor to decide what is best for your needs. Also keep in mind, every complex is governed differently, as to who is responsible for what. I showed a condo (townhome style) yesterday in which the owners is responsible for their roof and snow shoveling. This is rare, as in most complexes in my area that isn't the case. So be sure to ask for a copy of the bylaws ahead of time to clarify any of these issues!
In my area, condominium complexes are more prevelant than cooperatives, and are popular with first time buyers, and empty nesters, as they usually offer amenities such as pools, clubhouses and tennis. Many like the "care free" living a condo (or coop) offers. Buy what works best for you and your lifestyle. Everything is a bargain today.