There already are some very impressive games online at RPG Playground. However, there are also many games online, where creators only put about five minutes effort in them, or which are only tests. Therefore, pretty remarkable games of high quality will be drowned in all the tests, demos and incomplete stuff. If a player would like to play some (newer) games, created with much effort, there is almost no chance to spot them, if we put not much effort in it for searching them.
Quality seals could help us out. For every seal, we could have minimum requirements. They would not only help, to filter games with remarkable properties, they also would motivate creators to improve their games in order to receive them. You could introduce different of them, considering story, completion state, art skills, play time etc. Players should be able to vote a game for a seal. You also could let creators propose a game for one or more of the seals. A jury should decide, if game has already reached a state of quality.