Finding planner peace can be hard. There are so many different brands, layouts, colors and sizes. First learning what your planner needs are the deciding what kind of planner you are can help make those decisions a lot easier. When I first started I used composition books. That turned into a 3 ring binder, then a 6 ring binder, then I found my love for bullet journaling. Now I am testing the happy planners and I must say I am impressed and the fact that my stickers are made specifically for my planners is a huge help, because stickers.
Along the way of getting to where I am now I did learn a few things about my type of planning, which is why I think I will stick with the happy planner. The biggest thing being that I like to customize and move pages around. I did not like using binders because of how bulky the ringed side can be. But I can make the rings on my happy planner as big or small as id like (within reason of what is sold). I love those 2 solid facts! I also tend to plan in list form, however, sometimes the bullet point on my list can be rather long. So, I tend to lean towards horizontal layouts. Especially for business plans. The third thing I have learned about my planning style, that I have actually already mentioned. I love stickers. Just give me all the stickers in pink and purple.
All that to say there is no right or wrong way to plan as long as you plan. Any-who, here is a list of the current planners I am using or have used and the dimensions of their pages and boxes. Please let me know if I have missed or mis-measured anything so I can add it to the list.