Since you suggested ranking all the maps' gameplay on a scale of 1 to 10, I did that. In my own, highly opinionated and biased way.
Map | Score
2fort | 1
Granary | 3
Well (5CP) | I played this map maybe once and it was five years ago
Dustbowl | 7
Gravel Pit | 10
Hydro | 1
Well (CTF) | 2
Badlands (5CP) | 8
Gold Rush | 5
Turbine | 5
Fastlane | I played this map maybe once and it was five years ago
Steel | 10
Badwater | 8
Badlands (Arena) | I played this map in VSH and that's it
Granary (Arena) | I played this map in VSH and that's it
Lumberyard (Arena) | I played this map in VSH and that's it
Ravine | Literally never played this map
Well (Arena) | I played this map in VSH and that's it
Egypt | 5
Junction | 2
Watchtower | 1
Hoodoo | 3
Pipeline | I played this map maybe once and it was five years ago
Nucleus (Arena) | I played this map in VSH and that's it
Sawmill (Arena) | I played this map in VSH and that's it
Yukon | 2
Offblast | I played this map in VSH and that's it
Nucleus (KOTH) | 1
Sawmill (KOTH) | 3
Viaduct | 9
Harvest (KOTH) | 5
Harvest (KOTH, Halloween) | 5
Doublecross | 5
Gorge (A/D) | 10
Freight | 3
Coldfront | I played this map maybe once and it was five years ago
Thundermountain | 2
Upward | 10
Hightower | 2
Mann Manor | 2
Mountainlab | 2
Degroot Keep | 4
Gorge (5CP) | 3
Frontier | 10
Nightfall | I played this map maybe once and it was five years ago
Lakeside | 7
Badlands (KOTH) | 8
Barnblitz | 4
Gullywash | 6
Eyeaduct (Viaduct Event) | 8
Foundry (5CP) | I played this map maybe once and it was five years ago
Doomsday | 2
King (KOTH) | 7
Coaltown | 2
Decoy | 3
Mannworks | 5
Ghost Fort (Lakeside Event) | 5
Ghost Town (Coaltown Event) | 6
Bigrock | 3
Process | 8
Standin | 2
Helltower (Hightower Event) | 3
Snakewater | 7
Mannhattan | 2
Rottenburg | 2
Cactus Canyon | I played this map maybe once and it was five years ago
Asteroid | 2
Carnival of Carnage (Doomsday Event) | 3
Foundry (Mannpower) | 2
Gorge (Mannpower) | 2
Thundermountain (Mannpower) | 1
Powerhouse | 2
Snowplow | I played this map maybe once and it was five years ago
Borneo | 10
Suijin (KOTH) | 3
Brickyard | 2
2fort Invasion | 1
Byre | I played this map maybe once and it was five years ago
Probed | 5
Watergate | 3
Sinshine (Sunshine Event) | 8
Gored (Gorge Event) | 10
Hellstone (Millstone Event) | 5
Moonshine Event | 3
Hellfire | 1
Timbertown | 3
Landfall | 9
Vanguard | I played this map maybe once and it was five years ago
Snowycoast | 10
Highpass | 9
Metalworks | 7
Sunshine | 8
Swiftwater | 2
District | 2
Brimstone (Fifthcurve Event) | I think I haven't played this, not sure though
Maple Ridge Event | 8
Pit of Death | 2
Mercenary Park | 3
Mossrock | 7
Enclosure | 2
Banana Bay | 4
Brazil | 2
Lazarus | 10
Gravestone (Rumble Event) | 1
Cauldron | 10
Slasher | 4
Cursed Cove | I think I haven't played this, not sure though
Monster Bash | 9
Precipice | I think I haven't played this, not sure though
Laughter | 6
Bloodwater (Badwater Event) | 7 (we're talking about gameplay here, and in some capacity it's still Badwater)
Hassle Castle (Upward Event) | 10 (we're talking about gameplay here and Upward is lit)
Megalo | 5
Moldergrove | I think I haven't played this, not sure though
Snowfall | I know I haven't played this one
Pier | 5
Wutville | 1
Snowville | I know I haven't played this one
Erebus (Ambush Event) | 2
Terror | I think I haven't played this, not sure though
Graveyard | 10
Los Muertos | 5
Sinthetic (Synthetic Event) | I think I haven't played this, not sure though
Farmageddon | 9
Doublefrost (Doublecross Event) | I know I haven't played this one but it's no different to Doublecross gameplay-wise so it gets a 5
Altitude | 8
Bread Space | I know I haven't played this one
Chilly | I know I haven't played this one
Polar | 4
Cascade | 9