What's your definition of "best"? Best performance gains for the money? Best sound?
For intakes, it's mostly just a sound thing. The K&N Typhoon intake is comically loud at WOT. But mostly normal when just driving around. So I absolutely love it.
The JoeZ intake is just a smoothed out intake tube. To me that's not worth any effort since you still have the stock airbox and stock filter. Either stay stock or add just a different air filter, or go short-ram.
Exhausts...the ISS has the dif exhaust tips and sounds awesome. The Joez/PTS has the deepest/best sound.
Steve // 2008 IS-F / Starfire Pearl / 65k miles / Tint: Front 35% Rear 20% / JoeZ PTS cat-back exhaust / Beat-Sonic Nav+DVD bypass / Vaistech SL2Vi iPod integration kit / carbon fiber de-badged front grille / carbon fiber vinyl on lower rear bumper / S4Play rear diffuser / Escort Passport X50 / 80GB iPod in the armrest //