感谢您的关注 but with the change of different situations, the "attention" will mean differently.

in fact, when u translate something like this, u must consider about the culture. if u say "thx for ur attention" to finish ur speech, u can just say: 谢谢大家 if u want to say something to let others pay attention, u can just say: 谢谢 something like 谢谢您的关注 is correct by grammar but we d never said like that.

(文言) 承蒙關切 不勝感激

too many ways to say this: 1、多谢你的关注 2、多谢你的重视 3、感谢你的重视 4、感谢你的关注 5、谢谢你的关照 6、多谢关心 7、多谢关照 ... you can use these after you finished your speech, or someone replied your question, someone take care of you, and etc.