For the record? Heal Pulse is great in Double/Triple Battles, and Belly Drum is pretty much half the reason Azumarill is almost Uber-level overpowered. If you have Belly Drum on a Pokemon with really high HP and the ability to heal itself, it's absolutely broken.
Some useless moves, though... (I'm not including Splash, as it's a joke move intentionally not doing anything.)
Memento - It DOES have some really strong uses, but it's so situational that 99% of the time it's terrible.
Smog - I get that it's an early game move, but it's still terrible. At first you see it has 40% chance to poison, so for an early move that SOUNDS good... but then you see the move itself has 70% accuracy, and only does 30 damage. That means less than a third of the time you'll actually poison the target, and almost a third of the time you'll do nothing.
Synchronize - This move's awful. At first the effect is kind of neat, hit every Pokemon sharing a type with the user... but wait, that could be bad as well... you'd have to build your team around it, meaning it's situational. Situational moves aren't that bad, you say? True, but it's infinitely more effective and practical to just use Earthquake or Surf and have your allies be resistant/immune. Not to mention the odds of at least TWO of the opponent's Pokemon sharing a type with the Synchronize user isn't all that high. At least Earthquake has very high chances of hitting all three in a Triple Battle, and Surf is almost guaranteed. Oh, and let's not forget Synchronize is PSYCHIC type. Not all that much is weak to it, especially common types, and DARK types -are- common. Know what happens if a pure Dark type like Umbreon uses Synchronize? LITERALLY... NOTHING!
Leech Life - Again, it's an early game move... but a really, really bad one. Its damage is beyond horrible, meaning how much it heals you by is barely noticable. Pair this with not too many types being weak to Bug and a LOT resisting it, then the fact that anything using this is probably going to get KO'd in one or two hits... and it's just trash. Complete and utter trash.
Seismic Toss - Controversial choice, as it guarantees a set amount of damage... and while it CAN commonly hit harder than Dragon Rage and Sonicboom, those moves are early game moves that are actually DEVASTATING early on. Seismic Toss? Only inflicts damage as high as the user's level... guaranteed. If you're Level 10 and hitting consistent 20's with Sonicboom, or Level 20 and hitting consistent 40's with Dragon Rage... that's scary. Seismic Toss GUARANTEES exactly half that. At Level 100, that's honestly pretty terrible damage output. Doing equivalent damage to your level is plain horrible, as virtually any other option for your level is going to be better. You could make the same argument against Nightshade, but at least that distinctly gives you an advantage against higher level opponents, so while it's also pretty awful... it has SOMETHING special going for it.