My thoughts on Brazil vs. Thailand
In my opinion it is a tough choice as both countries have their strength and weaknesses. I have been visiting Rio and Pattaya for years. I speak Portuguese but not thai, which indirectly shows my preference.
Girls: For me Brazilian ladies wins hands down. On average sex is better and I find Brazilians more attractive. Prices are cheaper in Thailand though. If you want a live-in girlfriend I would think this would be easier in Thailand.
Food: Clearly a very individual choice. I do not particularly care for Thai food, so while Brazilian food is not the best in the world I prefer it to Thai food. In terms of cost Thailand is cheaper.
Safety: Thailand is the clear winner. It is much safer than Brazil.
Accommodation: Thailand is a clear winner in terms of value for money. Apples to apples Thailand is significantly cheaper and good condos or hotels can be had for at reasonable cost.
Groceries: I can find pretty much everything I want in both countries. Prices are lower in Thailand.
Locals: I would like to add this category as I feel the attitude of locals are an important part of how much I enjoy a place. For me Brazil wins this category as I, unlikely in Thailand, have never had the feeling that the locals disliked foreigners.
At the end of the day for me the decision depends on budget constraints. If I were on a tight budget Thailand would be a clear winner, while if money was less of an issue Brazil is a winner for me given my preference for Brazilian ladies and language skills.