Whatever it is, it has to be something that builds gradually over time. It took a while for us to realise the nastiness of Nick, then we got to watch him being nasty for a bit and getting more and more bold until he was uncovered. We had time for The Sun to do some serious investigative journalism to find out just how much of a git he'd been in his life prior to BB, and to do a campaign.
A feud that builds slowly could do it if they don't annoy too many of the others. There may need to be a 2-faced element to it, such as behaving in front of the others. 2 people competing for the affections of a lucky contestant might be fun. We had that a bit with Naz and Bubble both wanting to be Brian's best friend, but it could apply equally to romantic liasons.
What might be fun if an in the closet to the others gay person was being hunted down by a keen person unable to get the hint. We like the idea of being in on something that the others aren't. With Nick it was obvious, and with P&H we all got to see the hand-holding, talks of stuff and longing looks hidden to their housemates.
