Let's see ...
5. Jigglypuff - It has its uses, but they're really rather situational. The push she causes is easy to avoid and easy to actually survive anyway, although if you do get your opponent off the stage, it's pretty much the best edgeguard tactic out there.
4. Zero-suit Samus - It doesn't have much knockback, and you've got to be close to the person for it to hit; I don't know the specifics, but I think you could charge up a smash attack and hit her after the actual attack. It also forces you to return as Samus, a character many consider to be inferior, but whether that's actually bad depends on the person's preference.
3. Kirby - All it takes is an airdodge or a sidestep, and Kirby becomes susceptable to whatever attack you want to do. Even if he does get you, the damage and knockback are usually neglectable. Plus, you have as much access to the items made as Kirby does (if not more access) if you decided to turn items on.
2. Peach - Just like Kirby, except it actually helps you more. Unless your opponent doesn't know how to jump or grab a ledge, it's most likely not going to put anyone to sleep. I've heard that being close to her actually does damage, but look! Conveniently placed peaches are scattered everywhere for you to replenish yourself!
1. Lucario - The most easily avoided FS ever! Seriously, if you how to jump, double-jump, and Up-B (may be slightly different for certain characters, but you get the point), you have nothing to worry about. At most, you'll take minimum damage from an error and maybe the knockback from the final hit (which won't kill anyway).
Ness and Lucas get honorable mentions for being a bit easy to avoid; however, it does get harder to avoid in the end, and I'm pretty sure Lucas/Ness can move about at that time, so it's not terrible or anything.
There's my 2 cents, if anyone cares.