You're not going to get a lot out of an induction kit unmapped but it's a start.
Tegiwa's Mugen copy (or the Mugen if you're feeling flush) and the HKS Racing Suction Kit are probably the best two if you're not planning on mapping just yet and bolt straight on.
The Tegiwa has a tract that goes down to a scoop that you replace one of your fogs with, so most people remove both and have a non functional scoop on the driver's side. The alternative is to use it with something like the Driven Crazy scoop and leave the fogs in place. Very good intake temps with this kit. The kit is near stock in terms of noise you'll get.
The HKS is much louder, sounds pretty brutal on full throttle and in VTEC. It's an open cone that sits in the engine bay so it's wise to fit it with a heat shield. I did this along with the Driven Crazy scoop and on testing got just a couple of degrees above ambient temperature when on the move. I never experienced the dreaded heat soak that some people report in three years of running it.
The wild card is the Skunk2 intake. True open cone cold air intake, nice big intake pipe and again sounds great. I had this on the FD2. To fit the FN2 you need to trim a bit of body work and the back of the passenger headlight for it to fit properly, so not really a driveway job. Some people have said you get a flat spot without mapping but I didn't in the day I ran it unmapped on the FD2, though different ECU to be fair. The Skunk2 has been shown to give some of the best gains on modded, high flowing setups, so if you're thinking long term it might be worth going for.
Pretty much everything else on the market has issues where those above don't other than what is mentioned and then they don't give the same gains as those mentioned above so really I'd only consider those three.
