My philosophy on foods is, broadly, I'll try anything twice. Why twice? Because many times, the first time you try it is too traumatic or wrought to really know if you like it or not. And also, tastes change. So... here is my list of foods that I've tried once and don't look forward to trying a second time (but resolve to do so anyway):
1. uni (this is sea urchin ovaries, for those of you who don't keep up with sushi)
2. ants (they were actually fine, if a bit stale, and quite leggy, but I admit having a hangup about bugs)
3. durian (in truth, I only had a durian candy, but it didn't make me look forward to the real thing. nonetheless, someday...)
4. rocky mountain oysters (I ate one on a dare in high school, but I don't remember anything about it)
There are probably more, but I can't think of them.