Cheap and excellently positioned for the Roman port remains and the castle. No breakfast while I was there [proprietors away] but a €5 reduction to compensate.
To find it:
1. Get from Magliana on the Rome metro to Ostia Antica [five stops.]
2. leave the station and take the minor road straight ahead.
3. Cross the high bridge.
4. When you reach the house with 5 on the gate to your right come back one and BINGO!
Very comfortable and friendly. Good place to eat in the castle grounds.