I'm no specialist or professional, but I've had a little share of C, C++ and Pascal (but not Object Pascal).

To me it's those little things like ranges or subranges like 0..17 or something like that which -- as I remember -- cannot be done in C or C++.

Or what about...
[pascal]
with Thing do begin
value1 := 7;
value2 := 10;
value3 := 1;
value4 := 2;
value5 := 344332;
{etcetera}
end;
[/pascal]
...that instead of...
[pascal]
Thing.value1 := 7;
Thing.value2 := 10;
Thing.value3 := 1;
Thing.value4 := 2;
Thing.value5 := 344332;
{etcetera}
[/pascal]

If I recall correctly a similar thing -- the use of with-do -- cannot be done in C or C++. It's just a beautiful simple elegant touch that is effective as I see it.