It’s easy to locate my desk/work-area at work: just look for the toys displayed on a cabinet above a cubespace. I tend to go in phases, over a period of weeks/months of adding to or building a ‘collection’; after a lengthy Robin (Tim Drake) run, I cleared the cabinet, and restarted with Leonardo, Ninja Turtle.
Initially I started with taking in several of the "basic" figures from the various toy lines over the years. 1980s, 2003, 2012, the "Original Comic" line, and even the 2014 film line. Then I found the Classics figure, the Funko Mystery Mini, and the miniature version of the 2003 figure.
Since starting, I’ve acquired the miniature 1980s figure, the two mini 2016 film figures, and the MegaBlox 2012 figure along with the plush.
And while helping clean out my parents’ garage, I found what I think was some sort of Kids’ Meal toy, presumably from Burger King back in the day (based on the 2003 animate series.
In addition to these I have quite a few Leonardo "variant" figures primarily from the 1980s line.
The larger quantity of figures I started with of Leo is why I went with him as the focus…and he’s "traditionally" been my favorite Turtle (though I’d say in recent–the last 10 or so–years that has shifted to Raphael).