#1) Goodyear Eagle ResponsEdge, $599 installed @ America's Tire (matched TireRack price), High Performance Touring/All Season, Driven 50 miles
#2) Southern California
#3) Commute
#4) 50/50
#5) Bridgestone Potenza RE92A
#6) Cornering and general ride are the first things I've noticed since switching. The sidewalls are carbon fiber renforced which seems to make the car track better. The have some of the best ratings for snow, so I'll update this once I get a chance to run them in snow.
http://www.tirerack.com/images/tires/goodyear/gy_eagle_redge_ci2_l.jpg