That's my 4 year old playing with my Star Trek and Star Wars Micromachines. I believe I have all but the 3rd large set in there, with several duplicates. Oddly enough, after going through myself and 3 kids, the only real damage is one of the Reliants had the entire rollbar/nacelle assembly come off, which is a real pain to try and put back on. I did remove just a couple that were my favorites, though.
I doubt we'll ever get another series like this, so I'm wondering, with all the 3D printing options available now, has anyone looked into getting some models made at about this scale?
Cutting it kinda close with the minimum age limit, but I guess if he's supervised, it's okay.
There have been some some other really good sets. Runner up would probably be the the Johnny Lightning series. I have a few of those too and they look really good (though, sadly, I accidentally broke a nacelle off my Voyager

)
They too made some puzzling choices: The main one is that the ONLY ship from DS9 is the Miranda class Majestic, which which saw for about seven seconds, before being blown in half. No station, no runabout, no Defiant, no Cardassian or Dominion ships. That's the only one from the show. No idea how that happened.
Interestingly, besides doing a "D", they also made a Yamato, which I snapped up on eBay, when I saw it (no saucer separation, in case you're wondering). I would've thought if they do any other Galaxy besides the "D", it would be the Odyssey. I guess not.
Unlike the MM set, this one was recent enough to get some "Enterprise" ships. Actually, it's just the NX-01, but they did make a few versions of it: The normal version, the "battle damaged" version from the third season (they insisted on making "battle damaged" versions of nearly every ship they made), and the mirror universe version. (I have the latter two).
Interestingly, they also made a Constitution class Defiant and Excalibur. I read there were plans for a Constellation as well (One of the few times, if you ask me, when making those stupid "battle damaged" versions would actually be worthwhile)
The Furuta set in Japan looks really good too. (I'd REALLY like the Equinox and Prometheus).
According to Memory Alpha, Hot Wheels has an ongoing set out now that looks pretty good as well.