Allright, I watched the second one. (I haven't seen Lain yet, so I don't want to spoil anything).
* technical stuff:
- The divx logo. You apparently ripped your footage to divx. This is a bad thing. You compress already compressed game-footage to divx to edit with and then you compress again when you make your distribution version. All this horribly increases the number and intensity of compression artifacts. Also, you can't edit accurately with divx footage; a cut at frame 2443 when editing might be a cut at frame 2446 when you're doing your final rendering. Read these guides
http://www.animemusicvideos.org/guides/avtech/ It's all in there.
- The aspect ratio seems messed up (the characters look stretched vertically).
* editing and timing:
- The editing didn't exactly explode with emotion at the song's highlights. I would really have liked to see alot more sync with the song, which means shorter scenes (more cuts) to create a flow more synchronised with the music.
- The idea behind the vid was good. There was a really clear story (or rather a fluent progression of emotive scenes, AMV's never really tell an actual story in my opinion). Key moments within this story were synced up well (like the moment where she falls through him as a hologram (or whatever he was)) or the wedding scenes.
- I haven't played FFX, but it was clear enough what was going on, that's very important in a video. You really only showed three characters in self-explanatory scenes, which kept things clear and followable.
All in all, good storytelling, but a little lazy in the technical and editing departments.

Pretty good for a second video in 5 hours.
I'd be interested to see what someone who's played FFX has to say about it.