Unlike New York, Chicago, or other cities with numerous places to see the city from hundreds of feet up, Baltimore is yet to have a skyscraper that large with another good observation deck. However, you can visit "Top of the World", an enclosed observatory on the 28th floor of Baltimore's World Trade Center. From the top, you will see panoramic views of the city, the harbor, and beyond. And remember, it's always best to visit on a clear day for the best view. It is well worth the price, and definetley a great view.
Another place to get a wonderful view of the harbor for FREE is atop Federal Hill, about a 10 minute walk from the WTC. From there, you can see the WTC, numerous other buildings, and the ships sailing by on the harbor. It's a good place to enjoy a great view or perhaps have a picnic.
Also, if you're staying overnight and you want a harbor view, try to request it or book it if it is an option. It may cost a little more, but you'll probably appreciate it as soon as you see it. To get a good view of the harbor, here are some hotels: The Renaissance Harborplace Hotel, The Hyatt Regency Baltimore, The Marriot Waterfront, and the InterContinental Harbor Court Hotel. There are also several other hotels which were not listed that have nice views.
