I will gladly prove to you that I exist.
Although all of my senses can be doubted such as my vision and my hearing (How many times has a magician deceived you or a ventriliquist fooled you?) If I can doubt that one cannot not exist simply by my seeing or hearing it.
On that note, i can doubt everyone and everythings existance even my owns hands and body. Althought I can succesfully doubt all material existance how could I be thinking? There must be a metaphysical aspect of existance we can call the mind. Although I cannot think for anyone else and therefore I cannot prove their metaphysical existance I must remember I am thinking now. More specifically doubting. By doubting everying The only thing I cannot doubt is my own mind or thought since it is actively doubting existance. Therefore since I doubt I am. Or if you would like to hear it from a less cartesian stand point I think therefore I am.
Feel free to disprove my argument you wont succeed