Based on cleanliness.
For Mumbai New Delhi Sector,
First preference would be Mumbai CSMT Nizamuddin Rajdhani, excellent maintainence and feedback mechanism. Got a call from Central Railways about my feedback of CR Rajdhani after my journey.
Yet to travel in Tejas Rajdhani Trains, have traveled in Previous Version good trains but CR Rajdhani is another level.
For...
more... Uttar Pradesh,
First preference would be LTT Prayagraj Duronto and continuing further to Varanasi and Gorakhpur by other trains or buses.
Excellent service in Duronto, at least before COVID 19 started.
My family traveled in other trains to Prayagraj (Varanasi and Gorakhpur trains you mentioned). Not that well maintained, at least 2 years ago. Now no idea maybe they are.