Pathetic tends to imply underestimation, not overestimation. That said, the most genuinely pathetic estimate I saw was the estimate that the Wii would experience a huge sales drop-off as soon as 2008 hit, as projected by a supposedly professional site which rather shot themselves in the foot in that regard by having Wii sales actually be negative for 2012 to allow for the PS3 to actually outsell the Wii that year on their charts. I don't think you can get much more pathetic than that, really: predicting that a system will slow down massively while its competition will speed up massively, and yet still having to make an impossible event occur 5 years down the road from the time of the prediction to make that even happen.
EDIT: How appropriate, Fishy Joe posted one of the charts from that prediction just before I posted this.
Sky Render - Sanity is for the weak.
