It took a while to grow on me, but I quickly found that there's more to it than driving around in circles.
Dedication from the teams, preparing for one race takes @ least a week, Daytona 500 has some teams working all year getting the car and back up car ready. Precision of a good pit stop (change 4 tires, fill the gas tank, clear debris, and make adjustments all in 13-15 seconds), drafting (side drafting/bump drafting), adrenaline rush as your favorite driving works his

off getting to the front of the line. About 200,000 fans, which for the most part is 3x's more than any football/baseball venue. There's a lot of energy @ races, more than any football, hockey, or baseball game I've been to. I am a baseball and hockey fan, but Nascar comes 1st.
Take Daytona for example, you have 43 cars all going about 190-195 mph side by side, sometimes 3 wide, and they are beating and banging the whole way. It's a beautiful site to see how skilled the vets are, and of course its fun to watch someone make a rookie mistake and take out 1/2 the field (provided Jr's not involved

).
Thinking about this season starting brings a tear to my eye

, it was a very hard 2005 season and long winter for #8 fans.
This is all my opinion of course, I like to think of NASCAR as an acquired taste just like any other form of racing or sport.