I will be traveling solo to Europe this September and would like some help with the must sees in the following cities: 10 days in Rome, Brussels and Paris.

Hi, Paris and Rome I adore but unfortunatly I am not a big fan of Brussels.
Where are yoy travelling from and which city are you arriving into and out of?

PS
Post this on the Europe site as well as you will get more answers

Tell me to shut up about Brussels if you wish (it's you holiday) but there is an excellent thread on Brussels/Brugge on the Europe forum.

Another vote to post on the European board, there's tons more people who read that one. IMO your itinerary is more important than the fact that you happen to be traveling alone.

Hi:
These are some obvious, touristy suggestions, but they were highlights for us on our first trips (and please forgive any misspellings):

In Paris:
-Notre Dame, both during the day and again at night when it’s lit up. Climb to the top for a great view of both the city and the famous gargoyles;
-The Louve;
-Walk along the Champes Elese;
-Go to the top of the Eiffel Tower in the late afternoon so you can see the view of the city, then stay up there as night comes on – you can see why they call it the City of Lights;
-Wander through the shops and bookstores on the Left Bank.
-Sit at any outdoor café in the evening for some incredible people watching.

In Rome:
-St. Peter’s Cathedral and the Vatican Museum;
-The Sistine Chapel;
-The ancient ruins near the coliseum, which are intact enough to give you a great feeling for the old Roman Empire;
-The Spanish Steps (more great people watching);
-The Pantheon
-The Piazza Navona
-Walk along the Tiber and enjoy the street artists
-Take a train south of Naples and visit the ruins at Pompeii. You can do the round trip in a day, and it’s was one of the true highlights of our trip.

Brussels:
I have to agree, our trip to Brussels was not spectacular (the rain didn’t help). The old Guild Halls were the only thing I remember, mainly because I love old architecture.

Have a great trip!

My daughter went to Brussels and Amsterdam last year for 10 days and loved Brussels so much she will be there again this May.
She was alone and stayed at the Hotel Welcome. They were so great about looking out for her and being helpful.
She is renting a car and going to Ghent this time.
I think you should post on the Europe forums for more opinions on where to go .. doesn't really matter if you are solo or not- it is about where you are going