Just got finished with Chase Field.
I ended up staying in the Arts District midtown area at the Wyndham Garden Midtown on North Second Street. Although the hotel itself is very dated and needs a bit of a face-lift, the people were nice and very helpful. The rooms are satisfactory. Nothing special. Lower end on the pride too. I paid about $100 per night.
However, the reason I recommend this hotel, and more specifically this area near Central Avenue is the ease of use of the light rail line. My hotel was one long block away from pick up and dropped me right at the door step of Chase Field. It was about a 10 minute ride and you can buy a 24 hour pass for just $4.
I loved not having to drive downtown, deal with traffic and not pay for parking. All the restr that are recommended by BPC are within walking distance of the stadium.
Have fun out there.