"Best Wireless Router" is subjective. You are going to get opinions. I use a Linksys WRT54G and it works great. I'm not going to post a detailed explanation because, since you posted here, you can get to google. Start researching it for yourself and see what best suits you.
Just as with most other computer equipment, the more you pay the better it probably is (in most cases). You could get a Cisco 1803W Integrated Services Router for $1500 or a Linksys WRT54G for $50. Both would do about the same thing as far as a home user is concerned but the $1500 cisco would probably perform all around better than the linksys for speed and reliability.
A good inbetween location is the Netgear buisness line of network equipment. For decent performance and reliability at a more managable price go for the Netgear FVG318 or FWAG114.
If your budget is very tight just get a Linksys WRT54G. If you are only going to have one or two clients it should work just fine. I have yet to see a dead one.