Sorry but the Gallon to Inch is pure rubbish for any fish larger than a neon. Case in point - Oscars. 10 inch Oscar in a 10 gallon tank? I don't think so!
Plan stocking for a ten gallon tank - - do not follow any size to gallon rules, they do not teach you to how to plan based on adult sizes, water parameter requirements, ratios, schools, territories, dietary needs etc.
Go to your local fish store(s) and see what your local options are. Spend some time, bring a piece of paper and a pen and write down the ones that really interest you.
Come back here and list the ones you liked and we will help you plan a stocking that can hopefully accommodate some of them. This way a) we are going by your tastes b) we are going by availability.
Things to automatically avoid
Oscars, plecos (algae eaters), any type of fresh water shark, goldfish, mollies, cichlids (including angel fish), gouramis (except dwarf).
It seems like I have written off a lot, but all of these fish need much more than 45 liters. (approx 10-11 US gallons).
Meanwhile - read these to learn about Cycling!
What is cycling?
Fishless cycling - VERY IMPORTANT!
Nitrogen Cycle
All of these links and more can be found here -
Beginners Research Center