I know, this is a list for the worst radio stations only, but I'm going to include my favorite radios in it too.
Best Radio Stations:
GTA 3: Lips 106, Flashback 95.6 and Chatterbox FM.
GTA VC: V-Rock, Emotion 98.3, Wave 103 and Flash FM.
GTA SA: K-DST, Radio X, K-Rose, Bounce FM, CSR 103.9, SF-UR and WCTR.
GTA LCS: Head Radio, Double Cleff FM, Rise FM, MSX 98, and Flashback FM.
GTA VCS: V-Rock, The Wave 103, Emotion 98.3, Flash FM, Espantoso and VCFL.
GTA 4: Liberty Rock Radio 97.8, LCHC, Radio Broker, Tuff Gong, K109, The Journey, JNR 108.5, IF99 and Electro-Choc.
GTA EFLC: LRR 97.8, LCHC, K109, Vice City FM and RamJam FM
GTA CTW: Anvil and Praire Cartel.
GTA 5: Los Santos Rock Radio, Rebel Radio, The Lowdown 91.1, Space 103.2 and Blue Ark.
Worst Radio Stations:
GTA 3: MSX FM, Rise FM and Game FM.
GTA VC: None.
GTA SA: Playback FM.
GTA LCS: Radio del Mundo and The Liberty Jam.
GTA VCS: Paraside FM.
GTA 4: San Juan Sounds, Massive B Soundsystem, The Beat 102.7 and WKTT.
GTA EFLC: San Juan Sounds, Radio Broker, Electro-Choc and Vladivostok FM.
GTA CTW: Deadmau5, The Alchemist and Sinowav.
GTA V: East Los FM, Radio Los Santos, Non-Stop-Pop FM, FlyLo FM, The Lab, Radio Mirror Park and blonded Los Santos 97.8.
GTA San Andreas has the best radio stations, being K-DST and Radio X my favorites.