I have shot 4 different .40 cal semiauto handguns and would rate them as follows:
1. Steyr M40 - accurate, unusual sights that are quick to aquire, great if
you get used to sights or have small-med. hands.
minimal muzzle rise, lowest bore axis
2. Beretta Cougar - accurate, often overlooked, awsome looking wood
grips in the special edition package out 1-2 years ago.
3. Walther P99 - changable grips very comfortable, well built, more flip
4. HK USP compact - well built, least accurate in my hands
You could do no wrong in any of these, some say Glocks, Beretta 92's, and CZ's are the best in 9mm, I love them in 9mm, but have never tried any .40 variant.