Here is the following list of some best Internet Service Providers located in Phoenix which you are looking for

Windstream
Phoenix, AZ, United States

Phoenix Internet
2922 W Clarendon Ave, Phoenix, AZ 85017,
United States

XO Communications
3930 E Watkins St #200, Phoenix, AZ 85034,
United States

Cable One Inc.
1314 N 3rd St # 3, Phoenix, AZ 85004-1749,
United States

Local Net
Phoenix, AZ 85015, United States

Integra
5055 E Washington St #300, Phoenix, AZ 85034,
United States

CenturyLink
4568 E Cactus Rd., Phoenix, AZ 85032,
United States

Deru
3443 N Central Ave Suite 1705, Phoenix, AZ 85012,
United States

Cogent Communications Phoenix
3410 E University Dr, Phoenix, AZ 85034,
United States

Accipiter Communications
2238 W Lone Cactus Dr # 100, Phoenix, AZ 85027,
United States