This is a hard question because everyone has personal bias. Trying to completely remove my bias the two best current NASCAR drivers, IMO, are:
Tony Stewart ---- A throwback to the "good ol' days" and he don't care to abuse the car. Will race until the wheels fall off and wants to win everytime he hits the track. Special K Schrader said on INCR last year that Stewart had the best throttle control of any driver he has ever saw in his life. I think his IRL/dirt background have helped him learn how to handle stock cars.
Jeff Gordon ---- Not a favorite of his but won't deny the talent he has. I do think he has lost a bit in the past few years --- and I think it's because of him living in NYC and not being as connected to the team as he used to be. I'll never forget qualifying for the Brickyard in 95 or 96 when he won the pole. He came off of 4 totally sideways and never let off and still managed to get the pole. He's definitely got the equipment to win it and he has. If you are strictly talking about NASCAR success I think Gordon has to be in the top 2.
Now, as overall racers go I think you've got a list of 7 or 8 guys who are great "racers" that are in NASCAR right now:
Stewart
Jeff Gordon
Robby Gordon --- I'm biased because he's my favorite but Rob is a good dude and a great racer. I was a fan of his back in the OLD CART days when he first broke into the sport. He can drive anything with wheels, and drives them all well. He's not had the success in NASCAR but you've got to remember that Gordon is the type of driver that don't practice much of the old "saving the car" technique. He drives it old school style and it does hamper him sometimes but I don't hold it against his ability - he's just determined to drive the cars as fast as they will go at all times. He's the only guy I've ever got an autograph from and I got it at BMS 2 years ago. He came out just a few hours before the race to his hauler to sign autographs and hang out with his fans. The man and little girl in front of me was a good story. She was about 6 and in love with him and had an old Cingular Gordon shirt on that was well worn. She asked her dad if she could get a new Robby shirt and you could tell the poor guy's heart was broke but he told her maybe next year but we just can't afford it today, kinda quite so not alot of people would hear. She looked disappointed but didn't say anything and asked Robby if he'd autograph her shirt she had on. He said which new shirt of mine did you have your eye on? She pointed one out and he grabbed it off the shelf, signed it and handed it to her and said it was a gift for her being his biggest fan. That little girl will NEVER forget that day and it even choked me up - Robby is a good person too. I know most every NASCAR guy probably has a similar story about them but I saw this one firsthand
Ken Schrader - Give him good equipment and watch him make the most of it. He still wins regularly when he ventures outside of NASCAR.
Jimmie Johnson - Did most of you know how great he once was on Motorcycles? I didn't until I heard him talking about his old days on his Not What You Expected XM show. Still not a big fan of his but gained new respect for him listening to that show all year last year. He sounds like a really cool guy when he's not in front of the cameras having to be PC. He talked about a story of him winning Vegas and then hitting the casino's last year. He said him and his group were at the poker table just hamming it up and drunk. Said that they were a bit loud but just having a good time and a lady working there was getting irritated with them and had a pit boss come over. He said about the time he got there and started hovering over us it came across the TV that I had won the race and showed me on the TV in the casino. He said the pit bosses eyes got real big and he looked at me and then the TV and then they started treating us alot better.
Greg Biffle - Another throwback, manhandler of a car.