In fact, the topic of Chinese languages, is really such a complicated & exhaustive subject, even for our Chinese.
Now I'd like to show you the main large dialects of China concisely, as follows,
1, Mandarin (based on Beijing dialect, but modified & standardized), and Tianjin dialect has a few different tones & slangs, but mutually intelligible with Beijing dialect.
2, Wunese (吳語), commonly spoken in 江蘇 & 浙江 provinces, the representative cities are 蘇州、上海、杭州..., some foreigners call it as Shanghainese (上海話), but it's not correct enough.
3, Cantonese (粵語), officially spoken in 香港 & 澳門 cities, & widely spoken in 廣東 province too.
4, Minnanese (閩南語), (pronunciation: Bân-lâm-gú), actually it can't be called as 台語, because it's just the dialect of Min Nan (閩南) zone, such as the cities 廈門、泉州、漳州、潮州..., so it's absolutely not Taiwan's own language.
5, Hakkanese (客家話), this dialect has been in danger of dying out, only spoken in some places of 廣東 province, also in Taiwan, & in overseas Chinatown. Most of Hakkanese speakers have turned to speak Cantonese fluently in daily life.