Which Roma Pass?

All omnia passes are a scam: they sell you an official Roma Pass plus a Vatican Museums' ticket purchased on the Vatican's site; then they put both in one gift box and ask tourists two times the money they'd spend getting the same things on the same sites by yourself.

All Vatican Museums' tickets include the Sistine Chapel, you can't see it without walking through the Museums.
The official Roma Pass costs 38.5 €, it includes the 72 hours transit pass plus two free entries at your choice. Most use it for the Colosseum/Forum/Palatine Hill and the Borghese Gallery. If you are not interested in the second free entry you can buy:

• An ATAC 72 hours transit pass for 18 €
• A Vatican museums skip-the-line ticket for 21 €
• A Colosseum/Forum/Palatine Hill skip-the-line combo ticket (to be used on 2 consecutive days before the 31st of December) for 14 €.

18+21+14= 53 €

Or: an official Roma Pass for 38.5 € + 21 € for a Vatican Museums' Ticket = 59.5. €.

Note that a 90 minutes ticket costs 1,5 € and it gives unlimited access to all surface means of transport plus one ride on the metro. Unlimited transfers included. Who needs a pass?

The omnia is a scam.

Dario has it exactly right: the Omnia pass is VERY overpriced so don't buy it. Go with either individual tickets to the attractions you wish to see or the Roma Pass + individual tickets to the Vatican. Even the Roma Pass is only worth the price if the math works with what you want to see and how you plan to get around.

We find that we use public transit very little in Rome as it's more fun (and often just as convenient) to walk. We'll buy a few individual BIT tickets (1,5 € each) and stick them in our pocket for spur-of-the moment use.

Editing to add: you had a previous question about booking a tour with an independent company (not a coopculture tour) for the Colosseum/Forum/Palatine? If you do this, your entry tickets are usually included in the price of the tour so you wouldn't be using the pass there.

I had figured as much, but I wanted to hear it from those “more in the know” than I...thank you so much for your replies! This site is an invaluable resource tool for the European traveler!! God Bless Rick Steves. I’ve been a “devotee” since he first began!!!