Most popular SMBX episode?

[Luna]

What do you think is the most popular SMBX episode (aside from The Invasion 2 and The Princess Cliche)?

[AirShip]

Actual era: Sub-Zero Heroes

Classic era: Tower of Biased series/ Star Expedition

[Cedur]

Not sure if you can pick out particular episodes from classic era that outshine all other episodes by popular opinion. There have been like a dozen+ great episodes featured over time. Plus I have my personal favorites but many don't agree with me lol

also just sort the episodes forum by amount of views or replies if you like

[SBells27]

probably Valterri's Island Revisited

[HeroLinik]

Actual era: Sub-Zero Heroes

Classic era: Tower of Biased series/ Star Expedition

Just to add to this, being pretty well-versed in the classic era myself, I do remember Mario Classic was also held in high regard. One source cited it as the "best SMBX project ever made" and was stated to have "amazing level design and gimmick choices". Considering this was made back in 2011, the gimmicks were impressive for its time (such as a dark cave light gimmick based around attach to layer events).

[Luna]

also just sort the episodes forum by amount of views or replies if you like

Not just the forums - YouTube in particular is also a big factor.