Thailand has some of the most "flexible" visa arrangements I have heard of if you are trying to stay a longer time. Right now I have a good friend on their 6th consecutive tourist visa (each extended, with no issue, at immigration). You just need to find out who is in favour (right now it is Vientiane) and go there. Be well presented, quiet and patient. You WILL win.
I have had every visa imaginable in this country (bar retirement.....too young) and have found that patience, respect and being unassuming brings superb results from most immigration officers. Knowing when to cede is important too.
Sure some countries offer 90 days on arrival to certain countries, etc, etc but we obviously don't want to be in "some countries".