Depending on what mood I'm in I'll either tie a san diego knot or an improved clinch knot. I like the san diego knot because it's sort of like a clinch knot, but it doesn't seem to give as much when you pull on it. It's just solid. For line to line connections, I have had the worst luck with the blood knot no matter how perfectly I try to tie it, so I use uni to uni. I've done much better with that one.
-Brian