The cheapest lower level tickets for a Suns game are generally found in corner and baseline sections on either side of the court. When choosing among these options, always choose the corner seats, as these are some of the most under-rated seats in the arena.
Most corner sections are well-angled towards center court which gives you comfortable views of both ends. Unless you simply want to be as close to the court as possible, pass on the lower rows in these sections and instead aim for seats near row 20. The elevation and angle from these rows combine for a great perspective, and you'll be close to the section tunnel.