We have used the Weed Terminator for years. They are locally owned and the staff is very friendly. They come to your house approximately every 8 weeks and treat your lawn with the appropriate weed killers for your particular lawn type. The homeowner waits 24 hours and waters the lawn. Then I don't think about it again and they lawn stays in great condition.
I think it is a very good deal, because you as a homeowner are not trying to figure out which products to buy and then having to keep the stuff at your house. Parking is not an issue because they come to your house.