Reasons why:I have been on the District line the most and it has Air conditioning and it has the S7 stock Central: Its the fastest Elizabeth Line: Fast and it feels like a national rail train but its operated by TFL and it goes a few stops out of London DLR; Its because of where the DLR passes [ The Docklands up to Stratford] Hammersmith n city: Destinations and tube stock, but what i do not like about it that the first about 9 stops is part if District and Circle Circle: Has the S7 stock and Air conditioning, but its the slowest line on the Tube Metropolitan: Its trains are good, but the Metropolitan shares track with District, Hammersmith and Circle Line and Circle and passengers have to wait for a specific Metropolitan Line train which leads to platform congestion I cant share why all of them are good and bad bc its gonna take ages
BTW THIS IS MY OPINION