There is a lot that can be said about something so simple and seemingly insignificant as fishing knots. I’ve heard discussions on knots get as heated as speaking about politics and like politics, there is seldom a right or wrong as it often comes down to individual philosophies or needs.
I have tried and used a number of different knots in different situations over the years and typically I fall back to the ones that I am comfortable with and can tie with confidence. I like the blood knot for tippet to leader because it just looks good but I have to admit that the triple surgeon is likely a stronger and more versatile knot. I tend to lean towards the nail knot for line to backing or backing to leader despite most modern lines coming with welded loops. Clinch knot for surface patterns and Rapala knot for subsurface and those round out my repertoire of knots most used.
If you talk to 10 different anglers though on what knots they use day in and day out, odds are you can get 10 different answers. Is there a right or wrong? Sure there is but if you are sticking within the realm of fishing knots and you are tying those knots correctly, whichever one you are using will seldom let you down.
If there is one thing that is consistent though, no matter what knot you use; lubricate it. Most monofilament and fluorocarbon lines will create a lot of heat and weaken at the point of cinching. A little spit goes a long way.