I liked living in a townhome. We had a middle unit in a building with 8 units (4 on each side). It had a small patio in front that was half shaded by an overhang and half sunny. It was surrounded by a wooden fence, and there was a small border garden there that was nice for ferns and shade-tolerant plants/flowers. So that was basically our "yard," and it was big enough for our grill and a small table and chairs. Our little patio provided plenty of privacy, and there was a row of trees just outside of our fence. The unit itself was nice, modern, and had big windows and bright spaces. It was fairly new and had the nicest laundry room I've ever had (including 3 houses) and two very large bedrooms, each with a private bath, in addition to a half bath downstairs. It was plenty of space for two people and one little dog! It was also a very short walk to the bus I took daily on my commute. Also, our HOA didn't seem to have a bunch of silly pointless rules, which was nice.
Our neighbors on either side were quiet and quite lovely people.
Cons:
The biggest one: there was insufficient parking. Other people have mentioned this, but it cannot be emphasized enough. In our case, each unit had one "assigned" space, but these were all 2-3 bedroom townhomes, so most of the occupants had 2 cars, and there were not enough unassigned spaces to accommodate all of these. Technically there was some "street parking", but the street wasn't wide enough for parking on both sides (it wasn't actually designed to have cars parked along it at all.) The parking shortfall led to constant strife and the guy on the corner got really fixated on it. Eventually there was a shooting in this neighborhood where three people were killed over a parking dispute (I'm not kidding . . . it was horrible.) From what I understand, this is not an uncommon problem in townhome developments: not enough parking for residents, and nothing for their guests. Definitely find out from the neighbors about parking before you buy!
HOA mismanagement: for one reason or another, our HOA hadn't taken care of the roofs properly over the years. It was mostly retired people who volunteered, and probably they were distracted by constant parking disputes and complaints! Right before we moved, we had to shell out $8K for a "special assessment" to cover the costs of roof repair. People with bigger units had to pay even more. So, as long as you have a big stash, this isn't a grave concern, but it's something to be aware can happen.
Common space/common wall catastrophes: At one point the neighbor diagonally behind us had a clothes washing machine overflow. The water seeped under the wall and damaged our flooring/carpets, baseboards. The insurance companies kept pointing at each other and neither one wanted to pay. That was a pain to deal with. Eventually our own insurance paid out for the damages, but it wasn't as straightforward as it would have been in an SFH. Also, there will be a dumpster or twelve . . . make sure your unit is not too near it/them, and be prepared to just ignore it when people make a mess around it.
I would consider townhome living again, but I'd be very particular about the community and specific unit location. I can see how a townhome at the low end of the market could really spell trouble.