Go to C:\Program Files (x86)\Steam\steamapps\common\mass effect\BioGame\CookedPC\Movies (or wherever you have Steam installed). Look for the following files:
BWLogo.bik db_standard.bik ME_EAsig_720p_v2_raw.bik
Back up these files to make sure you can put the game back in its original state. Making a copy in the same folder should suffice. Then open each file with Notepad and delete all the contents by pressing Ctrl+A then Backspace. Save the files, then Mass Effect should start directly to the title screen.