The quick answer is no - there isn`t any player that will play ANY disc.
At the moment, I don`t think any Blu-Ray player is - or can be made - multi regional for your standard DVDS. Plus, like standard DVDs, Blu-Rays have different codes for different countries (US is Region A, UK Region B etc.).
But the good news is that a LOT of Region A discs are playable on UK/Region B machines... check somewhere like: http://bluray.liesinc.net/ for specific details.