I've had the Plugable 5-Port 36W USB Universal Smart Charger for over a year. I take it with me on all trips, including business and family travel. Having five USB ports means I can charge everyone's phones and a battery at the same time.
Instead of plugging directly into the wall outlet, the charger has a 48-inch power cord. This is an important feature, because it means I can plug the cord into a hard-to-get-to outlet and set the charging unit itself on a table or desk. The model with 5 smart ports is $(removed), and the model with 2 smart ports and 3 universal ports is $(removed)