Homewood Suites near Arundel Mills (sharing the same physical building as the Hilton Garden Inn on the other side of the building) is a great place to stay if you're looking for the "suite" experience. It's not located at the mall area (it's on the other side of Highway 100), so you need a car really if you want to explore Arundel Mills. The breakfast offered by the hotel was pretty good and was different each morning, at least. I wouldn't call the breakfast great, but it was sufficient; if you are particular about breakfast or don't book a room with breakfast included (if that's possible), there is a Denny's across the street from the hotel. The hotel rooms were massive and the plasma TVs were a nice touch. Free internet is nice as well.
One drawback of the hotel is that the walls are pretty thin (even for a hotel), and I was kept up my first night there by children running up and down the halls and my last night by some folks in the adjoining room partying until at least 0200. I called the front desk by around 0130 and I believe they either sent someone up or called the room since it finally quieted down within 30min. All in all, I would recommend this hotel for those doing business in and around Baltimore/Arundel Mills.