I and my family are planning a trip to Rome, Italy this summer in the
late June to early July time frame. What are the Top 10 "must see"
tourist attractions for first time visitors to Rome? My wife and I are
in our later 40's and we will be accompanied by our two children, ages
15 and 20.

Hi othrie-ga.  

You and your family have a treat in store for you.  Rome is a magical,
beautiful city, filled to its borders with magnificence from
throughout its 2000 plus years of history.  One of the great things
about it is that you can walk through examples of so much of that
history.  Some buildings like the Pantheon are in almost continuous
use for more than two millenia.  I have tried to give you a sampling
of the Greatest of the Greats, sites that cover the span of Roman
history and comprise antiquities, art, and churches.

The address (street) of each site is listed at the end of each entry. 

Coliseum (Colosseo)
The great amphitheatre completed in 79AD by the Emperor Flavian; where
gladiators fought and men were thrown to the lions.
Via Fori Imperiali

The Roman Forum (Foro Romano)
The governmental, religious, and commercial center of ancient Rome.   
Via Fori Imperiali

Baths of Caracalla (Terme di Caracalla)
The great baths erected by the Emperor Caracalla in 212 AD as centers
of relaxation, social interaction, and no doubt, intrigue.
Via delle Terme di Caracalla

The Pantheon (Panteon)
The ancient pagan temple dates from 27 BC and is perfectly preserved
to this day; it became a church in Christian times.
Piazza del Panteon

The Palatine (Il Palatino)
One of the hills of Rome, site of ancient pre-Roman artifacts and
containing the ruins of palaces of imperial Rome. Mythical home of the
founders of Rome: Romulus and Remus.
Via di San Gregorio

St Peter's Basilica (Basilica di San Pietro)
The immense cathedral built on the site where St. Peter, the first
Pope, was buried after his martyrdom.  The dome was designed by
Michelangelo and his famous sculpture, the Pieta, is displayed inside.
The majestic colonade of columns and statues rims St. Peters Square
Via delle Conciliazioni

The Vatican Museums 
One of the highlights within the museums is the Sistine Chapel with
its frescos by Michelangelo, depicting the Creation as well as the
Last Judgment.
Rooms upon rooms of art comprising ancient through modern sculpture,
paintings, and tapestries.
Viale Vaticano

The  Borghese Museum (Museo Borghese)
The 17th Century seat of the Borghese family, the mansion is filled
with Renaissance sculpture and paintings by Titian, Rubens,
Caravaggio, among others.  The Museum sits within the vast Villa
Borghese, Rome's central park.

Piazza Navona
A great oval piazza, scene of ancient boat races (it was flooded for
these events), site of three major sculpted fountains by Bernini, and
rimmed by modern restaurants, apartments, and the small, but
magnificent church of St. Agnese.
off Via Vittorio Emanuele

The Spanish Steps (Scalinata) and the Piazza di Spagna
The stairway up to Trinita dei Monti was built in the 18th Century. 
The boat sculpture (Barcaccia) in the fountain at the base of the
steps in the Piazza is by Bernini.  Several of Rome's premier shopping
streets give off the Piazza: via Frattina, via Condotti, via della
Croce, via del Babuino.


The choices were mine based on a long residence in Rome, but I
verified the information for each entry in my Michelin Guide for
Italy:
 
http://www.thesavvytraveller.com/insights/series/michelin/europe/italy/1home.htm


A good website to check out in preparation for your trip is the Rome
official tourist website:

http://www.romaturismo.it/v2/en/main.asp

As they say in Rome, buon viaggio (have a good trip).

alanna-ga

Fantastic answer . . . much more than I expected to receive . . . very
well written and thorough. Thanks very much for your time and effort.

http://wikitravel.org/en/Italy

Vatican Museum, early in the day;
St. Peter's Cathederal (airport-like security controls, no pocketknives ...)
Colosseum
If you wish, the Pope's public audience at 11 o'clock on Wednesdays in
front of St. Peter's, but you should check.

And too much else to ennumerate without knowing your interests in
Roman, Christian or Renaissance culture.
http://www.tourome.com/tourrome.htm
http://www.tourome.com/
http://rome.city-discovery.com/
http://www.enjoyrome.com/
http://www.summerinitaly.com/planning/rome_sightseeing.asp

Ostia Antica (Rome's original port) and and Tivoli (especially the
Villa d'Este with 2000 fountains!) are nearby but out-of-the-way
places that are unforgettable. Villa d'Este and Hadrian's Villa just
below it make an entire day trip with a lot of walking. Pack a lunch
and water. Ostia can be a half day, but is so peaceful you might want
to lounge the whole day.

Ostia and Villa d'Este are closed Monday.

To do the typical tourist bit, arrange for a guided tour on an
air-conditioned bus (July can be beastly hot). They'll hit the popular
spots.

CARRY WATER.

I'll be at 139 Viale Spartico in late July!

A great answer, Alanna.

One thing about Rome is that there are just so many historical and
artistic sights to see, that your children may lose interest.  Here
are two site that address this:
http://www.forbeginners.info/rome/visiting-with-kids/
http://www.lifeinitaly.com/tourism/lazio/rome-children.asp

When our kids were that age, being rather disorganized, we didn't get
them prepared for sightseeing trips.  They and we would have gotten
more out of some trips if we had built up their interest before hand,
maybe with age appropriate books on the places and people, history,
even maybe a little of the language.  They can take it or leave it,
but if they see you showing interest, it may infect them.  Maybe a
family quiz ("20 Questions") at meals would be fun.

And keep track of your belongings; there is a good reason why Italian
men's jackets all have buttons or zippers on the inside pockets.

Regards, Myoarin