Personally, I especially like Guangzhou, a city with a strong cultural and historical background. If you recommend it personally, you can punch in the following attractions by referring to the previous trips.
Yuexiu Line: Zhongshan Memorial Hall, Yuexiu Park and Nanyue King Museum in Western Han Dynasty.
Liwan Line: Shangxiajiu Pedestrian Street, Chenjiaci and Liwan Park.
Tianhe Haizhu Line: Guangdong Provincial Museum, Haixinsha, Guang Zhouta and Sun Yat-sen University.