Just for sheer geekery's sake probably the ISDN talk.

For OMG eye opening factor the FreeBSD jails talk (how the hell is this thing still so buggy?) and the talk on unencrypted satellite links

For excellent follow-along value and dedication to ridiculously pointless cause the Freebox talk. "Technically I don't own this box so instead of risking damaging it I'm going to take the extremely long and entertaining route around, somehow involving Doom WAD files"

For showmanship probably the Tegra talk

> For OMG eye opening factor the FreeBSD jails talk (how the hell is this thing still so buggy?)

Because everything that complex is going to be that buggy.

With the bugs they found fix a constant number of them still remains.