The BEST? Thats too subjective....
For polymer Id recommend the Springfield XD, regardless of caliber. For a bit more metal, Id consider the Sig Sauer P226, P239 or (if .45ACP is your thing) the P220. But, the Kimber 1911, H&K USPs, various Rugers, etc., are also nice guns.
Which gun is "best" is far too subjective as any of these weapons can fail, yet many of them are also quite dependable. However, each one "feels" different and in some cases, are functionally different as well. So basically, its up to your needs and what fits you best that is the ultimate factor here.
I will say this, however; if you are wanting anything above a 9mm Id stay away from Glock (particularly when dealing with the .40 S&W). This is just an opinion....