My personal choice is Green Green Grass of Home, because unlike Love Train it's not an actual barrier, it's a passive defense. Love Train can be broken by the infinite rotation, but if the rotation was fired at GGGoH, then it would never be able to reach its target.

I've been thinking about this all day, and I think that GGGoH is probably the 2nd best defensive ability, the first being Gold Experience Requiem. GGGoH's ability has two things that make it amazing:

1. It's passive, the ability is directly tied to distance from the stand, which means that even if Star Platinum/ The World stopped time, or King Crimson skipped time, or even if Made in Heaven accelerated time, they would still be affected by the shrinking, since the ability takes no time to effect people.

2. It's not a barrier of any sort, barriers have two weaknesses. The first is that they will always be breakable, there's no such thing as an invulnerable shield. The second is that attacking will always involve some part of your body leaving the protection of the barrier. GGGoH avoids both of these drawbacks due to its nature as a passive affect.

Well, GGGoH and Love train are different.

If Cmoon activated, love train would be able to withstand it since its a dimensional gap so Valentines wouldn't fly away. However, GGGoH only makes halves the size of things that approach it so it would be affected by gravity.

Same thing with cheap trick, since it automatically appears on the back of the victim, GGGoH wouldn't shrink it.