Regular gouramis will get big for a 10 gallon tank. They will also get aggressive. Dwarf gouramis are more peaceful and remain small.
Keep in mind, there is a general rule of 1" of fish for every 1 gallon of water. Therefore, you should not exceed 10" of fish in a 10 gallon tank. Typically, this is calculated for normal long, narrow bodied fish, such as tetras, danios, rasboras, etc. Wide bodied fish, such as angelfish and discus are usually given about 2"-3" of fish for every 1 gallon of water. Unfortunately some fish also have minimum tank requirements.
There are excpetions as well as far as stocking. It is possible to exceed the stocking limits if you have a balance tank, such as top/middle dwellers (gouramis, angelfish, discus, etc.) and also having bottom dwelling fish (plecos, loaches, etc.). Both types will not interfere with each others areas. Keep in mind that if a person were to exceed the stocking limits, you must have more than adequate filtration and must keep up with tank maintenance.