When I think of accommodation in Porto I immediately think of João and Lada River House. This is the second time i lodge here and I can tell you it won't be the last!
João is an amazing host and probably one of the best hosts I've ever had to pleasure of encountering on AirBnB. The location and customer service makes it feel like a 5 star hotel. On top of that he knows the ins and outs of the city and is very willing to recommend restaurants and book them for you; all for a hassle free holiday. I found I could enjoy my trip without having to think oh where should I eat a great meal?
Furthermore the apartment itself is drop dead gorgeous. And you cannot ask for a better location. It's close to pretty much all the major attractions and with the proximity to São Bento it's also perfect for the further journeys. If you are renting a car there is space to find parking along the streets, so anybody renting a car should not worry about parking too much!
If you are travelling from the airport it's easy to jump in the metro to Trinidade and then switch to the yellow line towards Sant. Ovido to get off at São Bento. It's quick and easy.