"Best"... that's a very broad and not very specific criteria. It's also very subjective, and you're not likely to find many people who agree on the same answer.
"Celtic" is also applied to a very wide variety of music; it's hardly realistic to compare a fiddler accompanied by bodhran to a celtic punk act.
I'm not really sure what you're asking here.
I have two modes: wiseass and dumbass. Mode is determined by current blood alcohol level.
Drinking is a sport. In order to be competitive, you must practice on a regular basis. Although you can practice alone, it is much more fun to practice with friends. If you're out of shape and practice too hard, you will regret it the next day.
Life is a disease. It is sexually transmitted and always terminal.