I have ridden a train twice. Once at seven years old, big adventure with my parents in 1958 and once on Amtrak that was a disaster.
well, there are some great trains to ride - but in the USA not so much.
Some great train rides that I have traveled:
1. The Sydney to Melbourne ride - awesome
2. London-Edinburgh
3. London-Paris (eurotunnel)
4. Lyons to Madrid
5. Bombay to Kodungallur
6. Geneva - Zurich
7.Bullet train from Beijing to Shanghai
8. Literally any Shinkansen line