Any terminal command does not work.

You messed up your PATH environment variable.

/bin/ls

works because you did not need PATH to find the 'ls' program. You can run ANY command by specifying its full path.

You need to re-edit your .bash_profile to either remove your PATH, or fix it. I do not know what editor you used to modify .bash_profile to begin with, but you can use

/usr/bin/nano

/usr/bin/vi (ONLY if you know vi/Vim)

/usr/bin/vim (ONLY if you know vi/Vim)

/usr/bin/emacs (I shutter to think about this)

TextWrangler (a very good free GUI text editor) <http://www.barebones.com/products/textwrangler/>

Or you can just rename the current .bash_profile and start a new terminal session, then fix the renamed .bash_profile before putting it back in service

/bin/mv .bash_profile saved.bash_profile

And while your echo $PATH kind of looked OK, it will not show any spaces or non-printing characters that go into the environment variable. Please use the following command and post the results

echo "@@@${PATH}@@@" | cat -vte

The @@@ will make sure we see any white space between the @ and the first/last character in $PATH

The cat -vte will convert any non-printing characters into notation such as a tab will display as ^I and the very last character will be a $ since echo adds a newline to the output, and cat -vte will display $ for that echo added newline.

That will show us a clear picture of what your PATH environment variable looks like.