Counterspelling

[Garan]

The PHB is somewhat unclear on this topic. It says at the beginning of the entry by saying that "It is possible to use any spell as a counterspell". However, it later says that "As a general rule, a spell can only counter itself."

So which is it? Or is it up to the DM?

[Jack Zander]

Any spell can be used as a counter spell... against itself.

[Coidzor]

Dispel magic-like spells I think are the few universal ones.

[Flickerdart]

Any spell can be countered by several things. They are:
-The same spell
-The "opposite" spell (Haste/Slow, Daylight/Darkness and so on)
-Dispel Magic and similar
-Improved Counterspell, Divine Counterspell or a similar ability that lets you change the usual rules

Thus, all spells can be used to counter themselves, and sometimes also a different spell too.

[Psyren]

Any spell can be used as a counter spell... against itself.

This. Not sure how it could be read any other way tbh.

Plus the additional cases Flickerdart mentioned.