Snorlax...we might see a big drop in usage of chibi Totoro. It already started to decline since Gen 4. It didn't really get anything new, and the environment around it has evolved.
The PotW's have been getting messier ever since 2/3 of the way in Gen 4. That's why I liked them so much more than Smogon's. Recetly, they seem to have gotten sloppier. Hopefully let's see something better in Gen 5. Personally, I'm not condemning the Samurott set because it was the Pokemon's fault.
Aggrolax @ Choice Band/Life Orb
4 HP/252 Attack/252 Special Def
Adamant (+Attack, -Special Attack)
Immunity/Thick Fat
Retaliate/Return/Body Slam
Crunch
Pursuit/Selfdestruct
Focus Punch/Fire Punch/Earthquake/Fire Blast
This is the generic CB'er set, with the possible addition of a strong Retaliation. Snorlax is notable with Retaliate as it has the bulk to consistently switch into attacks, as well as the movepool to deter any Steel, Rock, or Ghost switch-ins. Personally, I'm not a great fan of Retaliate, but it works. Otherwise, you can use a normal CB set.
Defensive @ Leftovers/Life Orb
252 HP/252 Def/4 SpDef
Impish (+Def, -SpAtk)
Thick Fat
Rest
Sleep Talk
Return/Body Slam/Double-Edge
Whirlwind/Crunch/Earthquake
Snorlax is the more offensive version of Blissey. Yeah. You can apply 252 Atk if you want to be more offensive. This is notable in being to handle Reuniclus more effectively than Blissey with moves such as Double-Edge, Whirlwind, and/or Crunch.
Tank @ Leftovers/Life Orb
252 Atk/252 SpDef/4 Def
Adamant (+Attack, -Special Attack)
Thick Fat
Return
Selfdestruct
Crunch
Earthquake/Fire Punch/Fire Blast
A mix of the first two sets, it retains all the power while having free reign of its moves. This Snorlax is more focused on smashing things through, impatiently spamming whatever attack suits best at the current situation. Selfdestruct ends everything, and despite the nerf, it's still powerful, especially with STAB. Crunch will eventually down the likes of Reuniclus between pure power and Def drops, and Earthquake is necessary to decimate Steel-types, especially Heatran. However, Fire Punch is always out there to hit Air Ballooners, Skarmory, and Bronzong. More importantly, aside from Scizor and Forretress, Fire Punch helps nail Ferrothorn.
SubPunch @ Leftovers
120 Attack/136 Def/252 Special Def
Careful (+Special Def, -Special Attack)
Thick Fat
Substitute
Focus Punch
Crunch
Body Slam/Return
Snorlax's ability to force many switches alongside its natural bulk makes a Substitute set pretty darn effective. Focus Punch and Crunch are a powerful combination resisted only by Toxicroak and Heracross, both of whom are greatly threatened by a Body Slam or Return. Return outpowers Focus Punch on average, but Body Slam's Paralysis rates come in very handy.
Belly Drummer @ Chesto Berry
120 HP/136 Def/252 Special Def
Careful (+Special Def, -Special Attack)
Thick Fat
Belly Drum
Rest
Return
Crunch/Earthquake
This is extremely tricky to use. Not only is cutting half your HP is risky in itself, but like most boosting sweepers, Snorlax is very vulnerable to the opponent switching to a hard counter after it Drums. Also, when switching in Snorlax, you (obviously) cannot take even 25% of damage, otherwise you'll fail deeply in Drumming. On the upside, it sends Snorlax's Attack stat through the roof, and if your opponent can't bring out anything to effectively absorb BOTH its offensive options, there is little that they can do. Therefore, it is your team's duty to deal with this and for you to resist the urge to send out Snorlax ASAP.
Rentsy @ Leftovers
140 HP/252 Def/116 Special Def
Careful (+Special Def, -Special Attack)
Thick Fat
Counter
Selfdestruct
Return
Crunch/Focus Punch/Earthquake/Fire Blast
Another set ripped straight from Gen 4, Snorlax is one of the more effective Counter-users. It is a lure for Physical attacks, and has the bulk to reflect them without the reliance of Focus Sash. Assuming no Attack EVs or Nature, a Conkledurr's Drain Punch after two Bulk Ups only has a 67% of a OHKO. After Snorlax has exhausted itself, Selfdestruct will be its most powerful attack. In the meantime, Return is there as its main offensive option, and Earthquake or Crunch is the decision to battle Heatran or Gengar. For other Steel types, you would generally want Fire Blast, due to their lower Special Defence and also because Gengar isn't immune to that. Focus Punch is alluring if people try to play around Counter, but remember that STAB Return is still more powerful.
The Infamous Curselax @ Leftovers/Chesto Berry
140 HP/116 Def/252 Special Def
Careful (+Special Def, -Special Attack)
Thick Fat
Curse
Body Slam/Return
Selfdestruct/Rest
Earthquake/Crunch/Fire Punch
This goes without saying. The key to beating Snorlax is to find out what auxiliary move it has, and even then, it isn't a guarantee that you can take it on without seriously hampering your chances of winning. I'll let everyone else explain this set, as it's simple, it's easy, it's straightforward, and I'm busy.
The Final @ Silk Scarf/Leftovers
4 HP/252 Attack/252 Special Def
Adamant (+Attack, -Special Attack)
Immunity/Thick Fat
Protect/Curse
Last Resort
More attacks are possible, but the more you do that, the harder it is to use Last Resort. It depends on how well your team can set it up, really.
Pre-Evolution Corner
Munchlax @ Eviolite
236 Attack/36 Def/236 Special Def
Brave (+Attack, -Special Def)
Thick Fat
Return/Body Slam
Earthquake
Pursuit
Fire Punch/Ice Punch
Munchlax @ Oran Berry
Recycle
Curse
Return/Body Slam
Fire Punch/ThunderPunch/Earthquake
Other Options
Recycle Lum Berry I guess, but it eats up too much space. Also Special attacking options, yadda yadda. It does get Work Up though, so consider it an option. Seed Bomb is an option, but what would you use it for, really?
I just noticed: Snorlax gets Wild Charge. That's an option over any ThunderPunch.
See also: Smack Down, Bulldoze
Munchlax can run any of the other sets Snorlax can for LC. Stockpile Munchlax is also becoming popular. At least 156 HP EVs can make Leftovers worth it for Munchy.
Partners
Secret Power Skarmory could come in pretty handy. Skarmory in general is good to Snorlax, as it is with Blissey. Spikes and Whirlwind help scout and weaken opponents for offensive Snorlax, and in terms of defensive Snorlax, Snorlax has its own Whirlwind. The aspect of Secret Power also can make Skarmory effectively decent in helping to Paralyze Pokemon for Snorlax. This is especially appealing for Belly Drum Snorlax.
Doubles/Triples/Rotation
Between Earthquake and its wide movepool and stats, Snorlax is a team player. It's also not as vulnerable to Physical shots as Blissey is.