Here are the most egregious ones I find most often (other than the first pasuk of k”sh as stated above):
Asher Baranu Lichvodo (see midwesterner above) (changes meaning from who created us to who we created)
Lishnei Ufur (as opposed to Lisheinei Ufur) in the second bruchu (changes from sleepers in the dust to two pieces of dust)
Hodoo al Eretz Veshumayim as opposed to Hoddo al eretz veshumayim (in psukei dezimra) (changes from his glory is over the heaven and earth to praise for heaven and earth)
Ki Lo CHAlu rachamecha instead of Ki Lo chaLU rachamecha (in modim) (changes meaning from because your mercy never ends to because your mercy never takes effect)