Tires are so irrelevant. I always recommend like $200 tires for people in cars (17 inch wheels), they're like $100 if you have 15 inch wheels. Big wheels are a fad. Goodyear Assurance Triple-Tread, Michelin Pilot Sport A/S Plus... I have yet to evaluate Continental DWS Extreme, but i hear they're good, in decreasing order of expense. For 17 inch, $180, $140, and $110, last I looked, without mounting and balancing (so the Goodyears cost around $210/wheel; but again, 15 inch is $100/wheel base price, $130 mounted). People I know insist on buying tires they can get for $50-$70/wheel mounted.

I recommend these as all-seasons; otherwise Bridgestone R030A summer tires and Dunlop WinterSport snow tires if you're doing 2 wheel sets. If you have a real snow season, it's highly worth it.

And people tell me, oh, those are expensive tires. You know what? You can go 130mph on freaking TripleTreds in the rain and it's like the ground is bone dry. Stopping distance doesn't change; you can't hydroplane; and they corner and stop even better in the wet than your cheap tires do on optimal, dry road. It's worth it for something you're only replacing every year or two, especially since the tires determine your steering and braking capabilities--something you don't want compromised, ever, even if you actually drive the exact speed limit and slow down in turns and everything like you're supposed to. Stuff happens that you just can't account for; this is the worst risk you can ever take.

On bikes, the tires last thousands of miles instead of 80,000 miles (right... try 30,000; after 2 years you need to replace 'em anyway due to dry rot); but while you can get into $300+ a tire for cars, your super-high-end bike tire is going to barely scrape $100. Most good bike tires seem to fall around $50 with a kevlar bead unless you're getting into racing gear. You also have half as many tires to worry about.

Again, nearly the most important part (brakes are the other part), and pathetically cheap no matter what you get.