Helpless is not unconscious. The rules specifically call out that an unconscious (and not a sleeping, helpless, or otherwise disabled character) character is always willing. The rules also state that a willing creature gets no save against spells.

RAW, if you are unconscious (between -1 and -9 HP or have more nonlethal damage than HP) you don't get a save against magic.

If you are unconscious you also become helpless, but you can be helpless without being unconscious.