An awesome knot

[BlackVert]

This, and the bow line knot are pretty much all you need. It is easily adjustable and it holds strong after you position it, so it is kind of like a combination bow line/slip knot.

YouTube - How to Tie the Adjustable Bend by TIAT

just saying

 

[Ronin38]

Very nice.

You might like this one, too. Now an iPhone App!

Animated Knots by Grog | How to Tie Knots | Fishing, Boating, Climbing, Scouting, Search and Rescue, Household, Decorative, Rope Care,

 

[robo]

if you can tie a bowline and a clove hitch you are pretty much set.

 

[Black95GTS]

I used a full windsor myself.

Adam

 

[Zero Signal]

That's pretty cool, but if you have a long distance between the knots, it can be kind of a mess if it isn't taught.

If it needs tension, a trucker's hitch is they way to go and it can be adjusted easily.

YouTube - Knot Tying Instructions & Uses : Tying Trucker's Hitch Knots

I say the 4 essentials would be the Bowline, Clove Hitch, Sheet Bend and Trucker's Hitch.

 

[BlackVert]

trucker's hitch ...

the midshipman's knot is very much like the first one i posted, and now i'm starting to prefer it because it is a little quicker to tie.

windsor knot ... not as good as a windsor motor