I believe the appropriate phrase is "Try it, you'll like it." No might about it.

Goddamnit, you're absolutely right.

Most pedants would say that "Try it you'll like it" is a run-on sentence, while "Try it, you'll like it" is a comma splice. The pedants would then disagree about whether that splice is a problem. They're pretty routine through the 18th and 19th century even in the writing of educated people, usually in contexts where the clauses are short and there's no risk of confusion. Then Victorian prescriptivism fucked everything up and we spent a few decades being uptight about splices along the lines of split infinitives and sentence-final prepositions. I think we're in a more relaxed place these days but your typical magazine copy editor will probably still flag them.

https://www.youtube.com/watch?v=OHdPwRZt8_k

[Cracks knuckles in pedantic anticipation.]

We're gonna get it on, 'cause we don't get along.

Even Strunk and White concede: If the clauses are very short, and are alike in form, a comma is usually permissible:
Man proposes, God disposes.
The gate swung apart, the bridge fell, the portcullis was drawn up.

Even Strunk and White? Those libertines of language?

4: so many ad campaigns of my youth killed off by the recognition of Heliobacter pylori and its effects.

Baby shoes, you'll like 'em!

That was me, for better or worse.

this is a comma splice, stop doing it

11 is a comma splice. 9 and 10 aren't unless you parse "shoes" as a verb, in which case I have follow-up questions.

Descriptivism, mass literacy, class distinctions; pick any two.

12 or unless you parse "baby" as an imperative verb which actually makes more sense. If you take excessive care of your shoes, you will grow to like them.