Just finished Single Player and Co-op yesterday eve, I must say that I enjoyed it very much so, only con I can find in this portal is that you kinda saw things coming, but that's about the ONLY con I can find.
Also for the conspirators out there. 2 days ago (19th), another rogue AI program would've gone online, called "Skynet". (lol, terminator)
And today the apocalypse will come, so keep your eye on the sky.

Also no, this ain't a "coincidental" thing, valve planned it to be so.
Btw, I collected mah 36 taters so I got 1 "free" portal copy (and a load of other games to gift), if anyone's interested to buy that (for a cheaper price, duh, prolly 30€), feel free to note me. ;o
Oh and Align, Portal IS sinister AND insane, that's why it's awesome.