Last week I stayed in Villa Verde with 7 friends of mine (all aged 19) and we enjoyed the holiday a lot.
The house is very big and cool as you can see from the pictures. The rooms are spacious and air-conditioned, the kitchen is fully-equipped, the yard is huge with a nice table and a great barbecue you can use and there's wifi all over the property. When we arrived it was perfectly clean and tidy.
It's situated in a little village on the hills (Poulades) so you will need a vehicle to move; a car is probably the best choice but, since in Corfu they don't hire cars to people under 21, we rented four scooters (50cc) and we were perfectly fine. The streets are a little steep and narrow but we managed to move with no big problems. Just a little tip: try to keep to the main ones.
The nearest supermarket (Diellas) and shops are about 3.5 km away and you will find anything essential. However, I'd suggest reaching the AB market in Kontokali (1.5 km further towards Corfu Town) to do your main shopping because it's better-stocked.
Regarding the beaches, we visited Paleokastritsa (very beautiful), Dassia (nice and close), Ipsos and Kontokali (close but not the best). Make sure to pay a visit to Corfu Town, it's not far but really cute. About night life, we've just been to Ipsos which is very touristic and full of Italian people but close and not bad.
Vicky, the owner, was very nice and warm. She called for our taxis every time we needed one, helped us rent our scooters, brought our bottled water up the hill, kept our luggage during the last day after we had left the house etc.
She was always available on the phone, plus she used to drop in on alternate days to water the plants and lives nearby so you can talk to her whenever you need to.
If I decided to visit Corfu again with many other people, I'd most probably choose this house.