There is no right answer for the question, because each of us are "rewarded" by different things, or fall in different places on the scale of instant versus delayed gratification. For me, while I totally understand the reward one feels from getting a challenging orchid to finally bloom, I personally feel much more satisfaction from the easy ones that regularly and reliably spike and bloom under my care. That's why I grow orchids, to enjoy the flowers, and the more often I can do that, the happier I am.
Quite a few years ago, I gave up trying to grow any type of orchid other than Phals in my house. They would grow new leaves, and the roots looked fine, but I could not get them to bloom. I didn't try a lot of different types, but oncidiums, paphs, and catts definitely did not seem to do well for me, so I figured they were trying to tell me something, and they were rehomed.
I now have a modest collection of about twenty Phals (all I have room for), and the most rewarding ones are the ones that bloom beautifully every year, or in some cases, ones that are almost constantly in bloom. There are several that I've had for two to three years that have either never bloomed at all, or were in bloom when purchased but never rebloomed. I will be looking to rehome those, too, if we ever get back to in-person society meetings.
The ones that grow and bloom the best for me are complex hybrid Phals, the winter-spiking type, some from orchid shows, some from Hausermann's, some from local grocery stores. And because they are so often in bloom, they are the most rewarding to me.
This is a fun thread, though, and I've enjoyed reading what it is about growing orchids that brings each of you a feeling of reward.