Townhouses may be convenient, but your appreciation potential is compromised. A house consists of two assets: the structure and the land. The structure depreciates like a car, boat, etc. Some homes have "antique" value and can, after a time, retain some value. The land, however, tends to appreciate in the long term at the rate of inflation, plus or minus. So with a townhome, you have less land (the appreciating asset). Moreover, in most cases, you're limited on what you can actually do with the land with a townhome (i.e., you can't tear down if you're attached to someone else!).
Here is some sales data for a couple subdivisions. The first is for a subdivision of townhomes with small (<2000 sqft) lots on W. Dallas. You see minor appreciation, probably less than inflation. The second one is from a nearby subdivision of single family homes with larger (>6000 sqft) lots and shows at least a doubling of property value over the same time period. Unfortunately the second one doesn't have that many data values, but you see my point. FWIW...