When considering tickets on the United Center's top seating deck, start your search with seats near center court. These will be the most expensive tickets in the 300 level, but they'll be much less expensive than lower level and club tickets. You'll also find that the views from these seats are far superior to all other upper level sections and much better than many 100 and 200 level options.
Unless you have mobility issues - or simply don't like walking up the steep stairs - consider the upper rows of these sections before lower rows in other 300 level sections. You'll feel much closer to the court and will never have to worry about the basket disrupting your view.
You'll find the best views at the front of each section in row 1. In fact, these views are comparable to the top rows of the club level but much less expensive. An even cheaper option is to target seats in rows 3 or 4. You'll still have a great view and be right at the entry tunnel that leads to the concourse and its amenities.