Well... for practicality and versatility, it would have to be one of my two current Olympiii - probably the E-M5.iii (because of its compactness, that I truly value).
But making the decision based on practicality or versatility sounds boring so... it would have to be the X-T5. Because of its insanely wonderful capabilities in the currently evolving Fujiholic universe of 'recipes' and SOOC film simulations which (warning: confession follows) I'm addicted to. Although, on second thought - or is it actually 3rd thought? - I might have to pick my Pentax KP. Because of its build quality, its unbelievably (to me, at least) high ISO capabilities... but mostly because more than any other camera I've used in years, it reminds me (in both expected and unexpected ways) of the ancient film Pentaxes that were my constant companions for several analog decades.
Is it permissible to have a photographic equivalent of M.P.D.? (Multiple.Personality.Disorder) Thus if I say I'm choosing only one camera - it also depends on which of my (multiple) personalities is doing the choosing on A.G.D. (Any.Given.Day) or, more likely, at A.G.H. (Any.Given.Hour)
And we really mean that.
Ooops... I mean I do.
Eye do.