"Either double sergons or blood knot. I like the 1st one more
Big fish (Tarpon, cuda, pike ect.) Bimini twist
Look here for instructions.

http://www.animatedknots.com/indexfishing.php?LogoImage=LogoGrog.jpg&Web...

Surgeons is easiest to tie tippet to leader on the river. For flyline to leader I usually get by just fine with perfection loops, but diehards will use a nail knot.

Blood knot or if you are on the river and need a quick knot I would try the surgeons knot or just listen to Alex.

I recommend Blood knot!!!

Bloodknot for mono to braid, double overhand for mono to mono

Blood Knot is what I use.

surgeons knot

The blood knot and here is why. I'm talking fresh water fishing not knots for big saltwater fish. I can tie a blood knot with a minimal amount of leader to trim off after I tie the knot, and that is important, not to save leader, but when you tie on a new tippet you don't use up much leader upstream from the new tippet, and have to now tie on a new section above the tippet in short order. I tie my own leaders, and can tie a slightly longer section of leader, and after tying the blood knot have the right section length, or very close. Knots that have lots of extra leader to cut off are difficult to figure. And I don't ever worry about the knot breaking. I never approach the breaking strength when playing a fish. It often breaks at the tippet blood knot when I am snagged on a bank bush, however, and then I am straight line pulling not using the bend in the rod to break off the snag. Takes practice, and you hold both tag ends just slightly through the center hole with your teeth, then you draw up the slack with your hands, and you have little left to trim off..wet the knot once formed, and before pulling completely tight.