Tons of factors go into it. There's personal preference things to consider: what terrain do you like? what landscape do you like? bowhunting or rifle?
There's priorities that you need to ask yourself. Everybody can think of the ideal hunting place, where you have 100% success, and there's no other hunters around. But you need to prioritize these things. Is it most important for you to get away from it all? Or is success the only ultimate goal?
Then there's other factual things to consider, such as: What kind of shape are you in? What are the hunting stats for a specific area? What is the herd health like there?
Other stuff: are you coming alone or with others? Pickup? ATV? Horses? what's your budget? do you have camp/hiking gear for wilderness hunting? etc. etc. etc.
I tell people to narrow down their preferences first. Find out what kinds of places are a good match for them - in other words, find a place where you'll have fun. Then narrow it down to where there's good numbers of animals.
This
article may be of help to you.
If you're interested in Idaho, I can help. PM me.