i dont see off by one as being particularly "C" family related, shows up everywhere you have sequences.
my computer history started with apple II peeking and poking, moved onto turbo c (oh the nostaligia) and then i lost interest when school tried to teach me pascal/modula - for some reason that was a very very uninspring and tedious way of interacting with a computer.
got to agree with CD that C# is the best at the moment, part c, part python - which java also tried to do, but failed at (probably due to pascal/ada influences hehehe)
Im a fan of the python because its so fast for getting work done, rather than fast at execution time, unless im on restricted hardware i dont waste much time caring about memory usage or cleverness, its not in my commercial interest

C# lets me be "fast at getting the code done" and still gives me the hooks to make the code itself execute faster (if someone wants to pay for it).
if i had time to program for purely my own pleasure, i think id spend more time doing haskell or ocaml - the bit of functional programming ive done made me want to get better at the no side effects, "provable" code approach.
and speaking of getting things done....