I know it breaks all the rules about diversification but I'm...

I know it breaks all the rules about diversification but I'm interested to judge HC posters' level of conviction.

If for some reason you could only hold one stock, of all the ones you hold or watch, which would it be? Why?

Most upside? No-brainer multibagger? Least downside? An industry with an assured future? Consistent dividends? Crash resistant? Great management?

I look forward to an interesting and varied selection of replies.

Cheers

Tony