Strongly suggest Bayphoto as a pro lab, also Whitehouse in Minnesota or on the border of Wisconsin. They also offer free UPS shipping of your prints. These are Pro photographer labs and offer very high quality at reasonable prices.
You say you are happy, however, you need to tell us more. You are happy with Wallgreens quality, compared to what??? You need to tell us what you are comparing them to, otherwise, there is no validation of their quality.
Wallgreens printing in general, is absolute rubbish, if you know what quality is, of course. If you have never seen a print from a pro photo lab, then yes, you might think Wallgreens is great.
Why do you get that feeling??? Because you just don't understand the problem. In fact, I get the feeling that you are part of the problem. A car going a bit over the speed limit or even faster on open roads is one thing. An idiot doing 90MPH and...