Any repair shop can replace the screen.
If you want the "best", first read reviews comparing original Apple screens with various third party screens (if you can find such reviews), then select the repair shop that has the best.
But for normal use (that is, for people who don't drop their phone) any screen would be OK.

Need to change the curtain! I need the best product. Where should I go, please help.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic