Topic's been a bit beaten to death here but.....
Money no limit? Long tubes. Most known will be the Stillen Gen 3 Long Tube Intakes. Retails ~$500. Better because of instant intake temps when idling. Tube's will still get warm but since the filters sit in front of the radiator and behind the bumper it gets cooler air just a bit faster than in-engine bay intakes. Theres a few similar to the design of the Stillen's. Keep in mind these can sometimes come up for sale in the Marketplace here for a bit cheaper but they usually get scooped up fairly quickly
On budget? Look into Post-MAF Tubes with some drop in filter like K&N, etc. These PM Tubes are silicone based i believe and are fairly thick so it minimizes heat and positioning of the MAF helps the ecu adjust to it better as well. This is still better than the stock intake boxes and tubes but seems to result in a few ponies less than the Stillen LT's. Boxes sometimes get a bit warm when driving for a long time so that's one reason why the LT's are slightly better than the PM tubes. Idk price but some used go for ~$100 so I'd guess there around $150 or so plus the drop-in filters for less than $100 or so.
There are also other variables that contribute to both options but I'll let you search for these yourself. Got a final soon so I decided to shoot ya quick anser
There are also a few dynos running around in the forum of each of these intake options so do some searching and I'm sure you'll find these. Look into the "Fang Vent Mod" as well. Some people do this as well to help the cooling in the OEM air boxes.
Happy Modding
And remember.. SEARCH is your friend! Lots of good info around here.