Oh yeah, Govan's another I should have remembered since I loved him on launch night.
This is just proof that VTs / early days in the house mean nothing. You can look like the most fun person in the world and end up being the angriest / bitchiest in there.
Another for me (a personal one, no idea if she was popular) is Rebecca (BB9). I thought she was gonna be great fun, and I even liked her during the first week or so, then she became a massive bitch.
There seems to be a trend of housemates looking like a lot of fun, and ending up being either annoying, miserable, angry or outight nasty. I guess that's down to a combination of playing up in the VT (kind of the opposite of those who play up to being nasty to get in) and being overexcited to go in.