If money is no object, here's another vote for the Hilton Suites (yum!!!). A close runner up is the Holiday Inn Suites on 17th st. I've never stayed at Francis Scott Key, but some friends with small kids have, and they loved it!!! You must cross the bridge to get to the boardwalk, however, it is relatively convenient to Assateague Is. which is a little quieter. Years ago, we stayed at the modern but not overly fancy Crystal Beach Motel ocean front 25th st. It has a small kitchenette (no stovetop) pool and very convenient location during the peak summer months. Also, check out the Monte Carlo Suites on 8th st. Again, not elegant, but very adequate and within walking distance to attractions. There are many options for small, older family run hotels that offer no frills and may be in need of updating. They are fine if you're planning on hitting the beaches or other activities.
A word of advice about condos; many require that you bring your own linens and have 10 am checkouts. That's rough when you're packing up an entire apt.