This question is inspired by this meta answer.
Applying for a tourist visa in a Schengen country gives you access to the entire Schengen area.
Generally, you should apply for the visa in the country you intend to spend the most time in while abroad. But if there are multiple countries you are looking to visit that fit this criteria, or you are flexible in your willingness to design your itinerary, you might want to apply at the country you'd have the best chance at.
Are there Schengen countries through which it might be easier to get a visa than others? i.e. countries that tend to approve more requests, have lower costs or documentation burdens, or are otherwise preferred?