Best way to get to Rome from Venice

Train. Hourly departures.
The sooner you buy, the better the price for nonrefundable tickets. They are like airline tickets, wait till the last minute and pay full fare.
http://www.trenitalia.com/tcom-en

Sam is right. Get on in Rome, get off in Venice and the Grand Canal is right outside the terminal door. Simple, fast and comfortable.

...would like to know the best (cheapest and efficient) way to get to
Rome.

Without a doubt, for me it would be by train: direct from Venezia S. Lucia to Roma Termini in 3 hours/45 minutes. I'm seeing one for the 12th at 9:25 AM that still has a economy fare available for 2nd class (the only class level we travel) for 64,90 euro if you book in advance.

An economy ticket mean you must commit to THAT train at THAT time or pay the difference between the reduced-price ticket and base fare as long as you do it BEFORE your scheduled train has departed. Reference this page for details about economy tickets:

http://www.trenitalia.com/tcom-en/Offers/The-economy-ticket

There are still super-economy (the cheapest) tickets available on the 12th but which involve a train change in Padova. Super-ecomony fares are non-refundable and non-changeable, and the 10-euro cost difference between that and economy may not be big enough for you to warrant having to change trains. It's not a big deal to do that but first-timers are often more comfortable getting from A to B in a straight shot.

Thanks! It looks like train is the way to go, booking the tickets today.

Wait a minute! I bet italotreno's discounted tickets are cheaper than trenitalia's.

Italo is a private competing railway company, not a reseller.

www.italotreno.it/en Checking takes only a few minutes.

Oh yeah, Italo is another good option.

I took Italo a few weeks ago and loved it. Turin to Florence.