I bought 2005 Impreza RS Wagon manual 9 months ago.
As you might know, 2006MY comes with lots of new features like 173hp (up from 165hp) and Head-thorax side airbag, i-active valve lift system, outside temperature display after $500 MSRP increase this year.
The things I like about the car are peace-of-mind AWD, powerful engine, rigid structure, proven reliability.
Also I like the brake system a lot (4 wheel disc brakes, EBD, 4 channel-4 sensor ABS).
Minor things are scratch resistant alloy wheels, squeak-rattle free even on rough roads, powerful A/C, boxer engine note, integrated antenna, woven seat trim.
I don't like things like lack of options (sports package is the only way to modify your car), crappy tires, road noise, so-so mileage (I get 10L/100KM on city without A/C), no cargo area light, frameless window, unstable cupholders.
I regret buying 2005MY because of the side airbag, but well new models are always better.
I could get $1000 off from MSRP and $500 free accessories last December.
So try to ask for the free accessories if they cannot give you more discounts.
Nonetheless, I can definately say I love the car.