I recommend the Eibach pro springs for a nice drop and better handling, will need an adjustable Panhard bar and front end alignment afterwards. Car looks much better then Stock 4x4 stance. The GT500's are popular choice, I had them on mine for 20,000 miles and wanted louder. Bought a set of used flowmaster hushpower axle backs and the car sounds great. But highly recommend the gt500's as they should have been factory issue for the 5.0 they sound fantastic. many go with a tuner/CAI combo to up the performance. I personally will wait until my 60,000 mile warranty is expired (20,000 miles left) as don't want to run the risk of denied warranty if something were to go wrong.
Like the others said visual mods or performance mods depend on the route you want to take with your car! It's yours now do what you like.
2011 Performance White 5.0 Premium 6spd MT, 3.73's, 401A
Mods: Staggered 18" FR500 wheels with 255 45 18, & 295 45 18 tires, Air Lift Drag Bags, Roush axle backs, Eibach Pro springs, BMR Adjustable Panhard bar, Center Fog grille, MMD Hood Struts,BAMA Tuned, JPC Line Lock, Blowfish Racing Bracket