jeeperjkjeeper

Not really a "part" but the best thing i bought so far is the professionally sprayed Line-x interior. ( money very well spent )

Red Wings

Poison Spyder evap skid. One of the first ones and now I don't have to worry about that anymore.

07crawler

my best buys so far has got to be the ARB onboard air kit, what a time saver, also my front stubby bumper from PureJeep...and lastely my EVO rockstars

jmat1980

Not that it is the best mod I have, but I am glad I got it...

The center console drop in tray. My JK is a 08 and they didnt add that until 09, but it allows quicker access to small items that always fell to the bottom of the console.

I also love the Tuffy concealed carry draw and my procomp 7069's that are sitting in my garage waiting for rubber in the spring

ArtsRx7

WARN 9.5TI I think I use it more than the radio lol.

wrangler07

ORTT Fold Down Table/Tool Box was another one I'm real happy with. I bought the smaller version originally designed for the TJ but they also have a bigger JK version. Again, not cheap but good solid kit that will outlast me.

Strong Bad

Atlas II T-Case and Dynatrac Pro Rock 60s for sure.

Also, wish I had just bought the 37 inch tires to begin with.

ytee

I know the title said favorite, but at least I did these two mods at the same time.
Going from 35" to 38" BFG's I could not believe how big a difference it made. There have been several places with the 35"s i could not go or would really have to beat on it to get, now with 38"s right up no problem. I also cannot say how much I like my PSC hydro assist steering!!!

wrangler07

Weathertech digital floor liners were another good purchase.

swpierson

Not really a part, but the cover king seat covers have really saved the seats from all the mud, snow, and salt the kids drag in and get on the back of the front seats.