I highly recommend the Century / Branson (they're the same tractor) lines. I just spent the last 2 months researching and studying tractors (I'm an engineer and have to really take things apart to be satisfied) After serious comparisons I bought a brand new Century 3647. It's a large 4 wheel drive with a 47 horsepower Cummins diesel. The tractor actually came with the same yanmar engine used in the john deere 4710 series tractor, but they just upgraded to the Cummins which is pretty bulletproof. I bought it from a dealer in the Houston area, and paid about 14,000 for (no loader no attatchments, just the tractor). I think it is on of the most powerful, heavy, and easy to operate tractors on the market.
It is made by Kukje out of Korea, and they're the ones who make the John Deere also, so don't be fooled into paynig more for the green paint.
Anthony