When I came to Thailand a couple of weeks back, I got an automatic 30-day visa stamped in my passport (US citizen).  Now the time is coming up for me to renew my visa and I'm thinking about which visa renewal option to take.  I know I can make a quick drive to the Cambodian border and get myself another 30-day visa.  I also understand I can take a more involved trip to a Thai consulate in a neighboring country and apply for a 60-day double-entry tourist visa.  If I opt for the latter approach, can anyone make any suggestions?  Malaysia or Singapore sound like my best options (I'd fly), but I'd love to hear about other's experiences before deciding which route to take.

Hahaha... read stopper's post on 'do not go to singapore' for visa.

Not too sure about the Cambodian border cause one of my friends was there, before he stamped out, the immigration guy actually told him that he is not allowed to enter immediately (since the exit and entrance is just on opposite lane) so he had to fly to indonesia instead.. u might not want to try your luck in this.

You might want to try out Mlaaysia. They have two Thai embassys there, one in KL and another one in Penang.

Not too sure about the Cambodian border cause one of my friends was there, before he stamped out, the immigration guy actually told him that he is not allowed to enter immediately

I suspect this was someone who had already done it many times in that case.  Do not believe a first time user would get such a reaction.

You might want to try out Mlaaysia. They have two Thai embassys there, one in KL and another one in Penang

In fact there in only one Embassy in any one country.  But there are Consulates at both Penang and Kota Baru that can issue visas and Penang has always been friendly to tourists.  Penang is also a pleasant train ride if you want to save some airfare.