If I could choose, and turn back time, I'd tour sections of South Africa (I lived there for most of my life) ...
I'd tour through places like Knysna/garden route:
Eastern Transvaal (that was the old name, I'm not sure of the new name now, as many/most town names were renamed after I left):
etc
I had a decent bike when I lived there (A Peugeot PX10, but I never explored with it (I did however tour to most places on a scrambler/trail motorbike... an amazing country with huge geographical diversity ... tropical rainforests in parts, and deserts in other parts).
I would not want to do this today though, as the roads have deteriorated , and it's not safe anymore
if I had to choose somewhere today, I'd choose Canada during the summer .... I've never ever been there, but have read posts on other forums from people who live there and I have seen photos ... looks like an amazing place to tour/cycle:
and saying that, I've only recently started cycling in areas close to me, that I had never been to before .... some really nice villages and scenery south of Cambridge