I guess there are many good starting points. One of them sure is the No More Heroes franchise: it's pretty accessible, fun and confortable.
If you are more into complicated plots, political fiction, deep themes and such, i would recommend you to start in one of the Kill The Past games.
You can maybe try starting the Kill The Past franchise with Killer7, which is an alternate universe and it's pretty damn fun though it may start kinda weird at first. The story is amazing and i do believe it's almost a perfect game.
If you like it, you should play the canon order of the original KTP games: The Silver Case, Flower Sun and Rain and last but not least, The 25th Ward
If you are even more into narrative and VNs, you can just start with The Silver Case and go through the order i just mentioned. But still: don't miss Killer7, it's a blast!