Raspberries. Raspberries are great. If I had to pick a favorite berry, I would go with raspberries. They're basically awesome in every way. Drawback? The price. Raspberries are expensive. You don't get good value for your dollar. So they're nice, but they're a luxury.
Blackberries. The problem with blackberries is they have a very narrow sweet spot of ripeness. Either they're overripe and too gross and mushy, or they're underripe and too tart. It's hard to find any that are actually ripe. They work okay if you mix them with something else, like in a pie or as an ice cream topping, but they aren't great for eating on their own.
Strawberries. They have that annoying stem on top. You have to do extra work with strawberries. Either you cut the stem off or you eat around it. Either way, you can't just pop em like you can with other berries.
Blueberries. There's your happy medium. Cheaper than raspberries, less work than strawberries, and more reliable than blackberries. Unfortunately, they are not as delicious as raspberries.
So blackberries are nice for pies, raspberries are a treat, strawberries are a project, and blueberries are a general-purpose berry-of-all-trades.
Grapes are nice too. They're like reverse blackberries: great to eat by themselves as a snack, but you can't really combine them with other things.