Secret Service Agent
On the criminal investigation side, you won't get much recognition from the general public, since most people aren't aware that Secret Service agents perform that work. If you apprehend a really bad actor (aka criminal), break a money laundering or securities fraud case wide open, or expose a foreign exchange scam, you'll get some kudos from the other good guys involved. Then you'll melt into the background.
Recognition for your protective work is a different story. It's really kind of bizarre that you don't get any recognition for your long hours, personal sacrifices, and job risks you undertake every day. However, if you thwart an attack on the President or other protectee, you'll probably get a mention on the nightly news. But not by name, of course. After all, you are the Secret Service.