Should I take the 30-day stamp and extend it or apply for a tourist visa for my trip to Thailand?

Get a visa..

For any stay between 31-90 days I'd suggest getting a tourist visa through the evisa system before you travel

It's fairly easy, you no longer mail in your passport as your visa comes by email. And it costs less than an extension from immigration if you're only staying 31-60 days plus you don't waste a day going to apply for your extension.

You don't say how long you're planning a trip to thailand for.

If you're just comin' for 2 months, get the 30 day visa exempt entry and take the one 30 day extension you can get on it. If you needed more time you could bounce out and back by land to get a new 30 day visa exempt entry (and extend that for 30 days too).

You wanna stay longer, get a single entry tourist visa from the thai consulate online in the US before you come, that will stamp you in for 60 days and you can extend that once for 30 more days

OR

Get a 6 month METV <- multi-entry tourist visa, which is good for 6 months, is unlimited entry during that time, each entry gets you 60 days, each 60 days can be extended once for 30 days, when that time is up you go to the border stamp out of thailand, in and out of another country and back into thailand to get a new 60 day entry stamp. You can get almost 9 months of stay out of an METV if you time the bounces/extensions correctly