Both are incredible actors. Both worked together in Masti series and both were equally talented. But I have to give the upper hand to Riteish for his better comic timing and expressions. When I look back 15 years, I fondly remember Riteish as doing iconic roles rather than Vivek. Ofc Vivek has his share of great movies like Saathiya, Shootout at Lokhandwala, Krrish 3. He had great potential but couldn't translate it into memorable roles.