Ones that can remove corrupt officials, not merely toothlessly impeach them to no actual end.

Ones that can call a new election on a dime (relative to the lumbering US system) and don't fetishize a Little King absolute ruler.

Looking about, Australia (as one example) took a hard look at both the US and UK systems and ran with a hybrid of their own design - "Washminster".

Australia has shortcomings, as do all systems, but they do have the ability to churn Prime Ministers at a quick pace until they get a good one .. with no great impact on the functioning of the country, they have proportional voting - and get a wider spread than a simplistic monolithic two party standoff as a result, better seperation of Legal, Civil, Policy, and Military than currently evidenced in the US.

All the same, there are 190+ countries in the world .. and the USofA is just one - and certainly not the poster child for a well run democracy.