This is the ONLY place I go for my alterations. It's clean, convenient (located on the West side of the San Tan Mall), friendly -- and most importantly, they always do quality work. They've tailored several bridesmaids dresses for me, along with some other less important articles of clothing and everything they've worked on has always fit perfectly!
The only reason for the 4/5 stars is price. This place charges more than most other places around the area but I believe that you get what you pay for!
They're open daily 10am-6pm, closed Sundays. Cash or check only. Be prepared to wait a while if you come at a busy time -- they have 2 dressing rooms which can fill up fast!