Depends where you're growing. Inside, I like clones better. Outside, I like seedlings.

Seedlings have a better, more hardy, natural plant structure. They can survive a strong wind/rain with minimal damage. You don't have to tie them up as extensively either. They also yield up to 40% more than their clone counterparts outdoors. Unfortunately, you better be prepared to brutally kill your largest plant, among about half of the others. The biggest ones tend to be male.

Clones are good because they are 99% female. And although they may not get quite as large as seedlings, they can still put up some serious numbers. I stated before that I'm not a fan of the bushy, unnatural structure of clones, and all the tying up associated with them.

Both have their flaws, and benefits outdoors. But I'd much rather grow clones indoors, since the plants never really get big enough to have to extensively tie, and I can't risk seeds.