The left one will break easier if you don't reinforce the joints properly. Too many people just throw nails into the joints and expect it to withstand people jumping onto it constantly. The other design may be a bit more wobbly, but it can withstand alot of weight.
Go with the left one, but use L shaped metal brackets and crossbars to reinforce it.
It's the batontwirlertwistshakebakecakeholehumperdinkkink rail.
t-rex with diagonal braces. Bury the bottom supports in the ground before the snow starts
Ski. Eat. Sex. Sleep. Ski. What else is there?
Dude, joke's totally on them, you should make a t-shirt that says 'all you fools suck' and on the back it can say 'I rule coz T-dawg said so' and yeah, you'll be rockin it shibby, new steeze brah, wikkid! ~PhattTim