What are everyone's ideas for improving post quality?

I have mostly ruled out:

 - Removing signatures or sig ads globally.
 - Requiring payment to wear sig ads.
 - Banning account sales.

A couple of ideas that have been floating around in my head:

1. To attain ranks above Member, you'd have to earn some number of merit points. Merit points would be awarded in a monthly vote on best posts of the previous month, with various measures (TBD) to prevent gaming of the vote. Winning merit points might also come with a BTC prize.

2. Create or designate some sections as "serious discussion" sections, with no signatures. In those sections or maybe in different ones, also have poster restrictions such as Member rank or above only. And/or allow topic-creators to set these restrictions on their topics, similar to selfmod topics.

What do you think of these ideas, and what other ideas do people have?