In terms of performance, reliability, fit and finish I'd say the Revo intake. It's noisy though, and it's not cheap. You will need a rubber bobbin where it attaches to the chain cover though, otherwise that section of pipe can sheer off.
The Racingline intake is also good for performance, but is also expensive, and the fit is terrible, so I would steer clear of that one.
ECS Tuning do a good intake, and there's a few from Europe but with import duty and VAT, they're also expensive.
The RamAir is a cheaper alternative and popular.
They all do the same thing and they all make a lot of noise (except the RacingLine) so buy which ever your budget can stretch to.
