Playing the steam release left me desiring to play the now 'classic' DF. Upon doing so I realized I never shared these advanced World Gen parameters I spent weeks or possibly months working on. I've probably spent more time messing around in advanced world gen than actually playing this game over the years I'd bet.
This parameter set has been designed to maximize available play area and generate tuned values of geography, civs, evil/good, beasts, cave params, etc... Often generates aesthetic and interesting terrain due to a higher variance. This is simply a template feel free to tweak it as you wish.
[WORLD_GEN]
[TITLE:The Garden of Conqueror's]
[NAME_SEED:wwoWIiMEwcicc6EuqIsS]
[DIM:257:257]
[EMBARK_POINTS:1669]
[END_YEAR:169]
[BEAST_END_YEAR:69:33]
[REVEAL_ALL_HISTORY:1]
[CULL_HISTORICAL_FIGURES:0]
[ELEVATION:1:400:369:369]
[RAINFALL:0:100:369:369]
[TEMPERATURE:28:69:13:69]
[DRAINAGE:0:100:169:169]
[VOLCANISM:0:100:369:369]
[SAVAGERY:0:100:769:769]
[ELEVATION_FREQUENCY:6:36:6:8:14:30]
[RAIN_FREQUENCY:6:1:0:0:0:1]
[DRAINAGE_FREQUENCY:6:40:5:8:8:16]
[TEMPERATURE_FREQUENCY:1:0:5:14:5:0]
[SAVAGERY_FREQUENCY:6:1:1:3:6:8]
[VOLCANISM_FREQUENCY:6:7:0:0:0:96]
[POLE:NORTH_AND_SOUTH]
[MINERAL_SCARCITY:2169]
[MEGABEAST_CAP:69]
[SEMIMEGABEAST_CAP:96]
[TITAN_NUMBER:3]
[TITAN_ATTACK_TRIGGER:100:0:120000]
[DEMON_NUMBER:13]
[NIGHT_TROLL_NUMBER:33]
[BOGEYMAN_NUMBER:33]
[NIGHTMARE_NUMBER:33]
[VAMPIRE_NUMBER:1]
[WEREBEAST_NUMBER:33]
[WEREBEAST_ATTACK_TRIGGER:50:5000:50000]
[SECRET_NUMBER:1]
[REGIONAL_INTERACTION_NUMBER:13]
[DISTURBANCE_INTERACTION_NUMBER:13]
[EVIL_CLOUD_NUMBER:6]
[EVIL_RAIN_NUMBER:13]
[GENERATE_DIVINE_MATERIALS:1]
[ALLOW_DIVINATION:1]
[ALLOW_DEMONIC_EXPERIMENTS:1]
[ALLOW_NECROMANCER_EXPERIMENTS:1]
[ALLOW_NECROMANCER_LIEUTENANTS:1]
[ALLOW_NECROMANCER_GHOULS:1]
[ALLOW_NECROMANCER_SUMMONS:1]
[GOOD_SQ_COUNTS:669:1169:2169]
[EVIL_SQ_COUNTS:669:1669:2269]
[PEAK_NUMBER_MIN:0]
[PARTIAL_OCEAN_EDGE_MIN:0]
[COMPLETE_OCEAN_EDGE_MIN:0]
[VOLCANO_MIN:13]
[REGION_COUNTS:SWAMP:0:0:0]
[REGION_COUNTS:DESERT:0:0:0]
[REGION_COUNTS:FOREST:6969:0:0]
[REGION_COUNTS:MOUNTAINS:4969:0:0]
[REGION_COUNTS:OCEAN:9369:0:0]
[REGION_COUNTS:GLACIER:169:0:0]
[REGION_COUNTS:TUNDRA:369:0:0]
[REGION_COUNTS:GRASSLAND:3369:0:0]
[REGION_COUNTS:HILLS:3369:0:0]
[EROSION_CYCLE_COUNT:369]
[RIVER_MINS:236:169]
[PERIODICALLY_ERODE_EXTREMES:0]
[OROGRAPHIC_PRECIPITATION:1]
[SUBREGION_MAX:5000]
[CAVERN_LAYER_COUNT:3]
[CAVERN_LAYER_OPENNESS_MIN:69]
[CAVERN_LAYER_OPENNESS_MAX:99]
[CAVERN_LAYER_PASSAGE_DENSITY_MIN:1]
[CAVERN_LAYER_PASSAGE_DENSITY_MAX:25]
[CAVERN_LAYER_WATER_MIN:0]
[CAVERN_LAYER_WATER_MAX:100]
[HAVE_BOTTOM_LAYER_1:1]
[HAVE_BOTTOM_LAYER_2:1]
[LEVELS_ABOVE_GROUND:15]
[LEVELS_ABOVE_LAYER_1:10]
[LEVELS_ABOVE_LAYER_2:15]
[LEVELS_ABOVE_LAYER_3:20]
[LEVELS_ABOVE_LAYER_4:25]
[LEVELS_ABOVE_LAYER_5:3]
[LEVELS_AT_BOTTOM:2]
[CAVE_MIN_SIZE:69]
[CAVE_MAX_SIZE:269]
[MOUNTAIN_CAVE_MIN:96]
[NON_MOUNTAIN_CAVE_MIN:133]
[ALL_CAVES_VISIBLE:1]
[SHOW_EMBARK_TUNNEL:2]
[TOTAL_CIV_NUMBER:169]
[TOTAL_CIV_POPULATION:33333]
[SITE_CAP:1369]
[PLAYABLE_CIVILIZATION_REQUIRED:1]
[ELEVATION_RANGES:3963:0:9369]
[RAIN_RANGES:669:0:3333]
[DRAINAGE_RANGES:1639:0:500]
[SAVAGERY_RANGES:669:0:0]
[VOLCANISM_RANGES:639:0:9369]