Well, I found the "Freemans Mind" Version of Gordon most interesting - he simply declares that everyone else went crazy and that the universe tries to kill him for no reason other than being "awesome".
Also, there might be some glad to hear (yes, I am talking to you two guys) and several who might forgot about "Black Mesa", the fan-made remake, featuring an enhanched version of Half Life without chaning much of the basic gameplay (Health Pick ups, no iron sight except for the Revolver, better visuals,...) without sacrificing anything what was good.
There was even recently a leak of a video of a very recent build of the mod (4 to 5 weeks old). It has been taken down from YT since then, but someone else downloaded it beforehand and uploaded it. You can get it here [http://forums.blackmesasource.com/showpost.php?p=474349&postcount=545]. (Check the rest of that threat to find a Q&A about that video a bit earlier on)
And yes, HL1 did age well except visually. Nobody can really deny that it looks pretty bad nowerdays (but there are worse looking games, which came later), even the HD Models kind of save it a bit from looking like absolute ass.