After a long international flight to Italy, all we want to do is sleep, eat Italian food, and then sleep some more. The problem is that Rome is not a great city for sleeping. And compared with the rest of Italy, it's actually not that great a city for eating. So we suggest that rather than spending your first night or two in Rome, head north to a little lake town called Trevignano Romano. Trevignano is just an hour from the Rome airport (about the same time it would take you to reach a hotel in the Roman Center). The lake is beautiful, the seafood is cheap and delicious, the wine flows like beer, parking is easy and free,  and hotel rooms are between $80 and $100.
We suggest B&B La Terrazza sul Lago. Nothing fancy, but it's located directly on the shore of the lake and you wake up to a view of blue water and hilltop castles. The owners are friendly and make a great breakfast (don't miss the breakfast cakes, some of the best we've ever had). It's about $80 a night and includes Wi-Fi,breakfast, AC, and a view. They have bikes available to borrow but if you're planning on heading to the nearby villages we suggest taking a car - italian drivers are not the most bike-conscious.
Spend your day eating mussels and white wine on the lake, hiking up the hill to the ancient ruins, and possibly visiting nearby towns.
The directions on the hotel website take you from the airport around the Roman Beltway. We find that can be confusing and can leave you stranded in Roman Traffic. We suggest taking the A12 straight up the coast and then cutting over. Directions follow:
From the airport, take the A12 towards Civitavecchia. That's North, but since Roman road sign's don't give helpful hints like directions, just look for Citiviavecchia.  
After 20 minutes or so, take the SP4a towards Cerveteri. It's a little town just a couple kilometers off the A12.
In Cerveteri you'll turn right - still on the SP4a - towards Bracciano (Bracciano is on the lake as well). The turn is just before you reach the center of town. If you don't see the sign, ask anyone for Bracciano.
After another 20 minutes or so you'll see signs for Trevigano Romano.The SP4a will take you around Bracciano and into Trevignano Romano. In Trevignano turn right anywhere to reach the rim of the lake. La Terreza is directly on the lake, in the center of town.