Taking the SI base units, which can be used to derive all the others that we know about :
Time, Energy ~ Mass and Length are quantified by Heisenberg's Uncertainty Principle.
Temperature doesn't really exist, it's kind of a proxy for information through energo-informatics, quantified, thanks again to the HUP : http://www.av8n.com/physics/thermo/entropy-more.html#sec-pha...
Electric Current by the charges being discrete.
Mole by definition.
Candela is not a physical unit (but one based on human biology).
----
Of course, that's a different question of whether their amounts in our universe can be (countably) infinite : so far as we know, time is (and maybe space, which should make other space-extensive quantities like mass-energy and charges also (countably) infinite ?)
We might never get a "theory of everything", and we shouldn't assume the existence of new physical properties without any other reason to do so, this goes against the principle of parsimony ! (Especially continuous ones, none of which seem to exist for now !)
And if our understanding of physics does change, it could have other dramatic consequences - that Bekenstein bound might not be valid any more for instance...
(yes, that's a ridiculously high bar, but still finite)
How can we know that? If memory in some way uses energy levels for encoding then we know it must be finite because of quantization but do we know that?