Pokémon Diamond and Pearl/Pal Park

To unlock Pal Park you must acquire the national dex(to get that you must finish the Shinou dex). To use Pal Park you insert a GBA game into the DS GBA slot.

Ruby Seedot -- Hakutai Forest, Route 203, Route 204 Nuzleaf -- Route 229 Mawile -- Iron Island Zangoose -- Route 208 Solrock -- Thrust Lake, Thrust Lake Surroundings, Wisdom Lake, Aspiration Lake, Tengan Mountain, Departure Springs, Return Cave

Sapphire Lotad -- Route 203, 204, 205 North, 212 South Lombre -- Route 212 South, 229 Sableye -- Iron Island Seviper -- Route 208 Lunatone -- Thrust Lake, Thrust Lake Surroundings, Wisdom Lake, Aspiration Lake, Tengan Mountain, Departure Springs, Return Cave

Emerald Pineco -- Hakutai Forest, Route 203, 204, 229 Gligar -- Hard Mountain, Route 206, 207, 214, 215, 227 Shuckle -- Route 224 Teddiursa -- Route 211, Wisdom Lake Ursaring -- Wisdom Lake, Route 216, 217

FireRed Caterpie -- Route 204 South Metapod -- Hakutai Forest Ekans -- Route 212 South Arbok -- Safari Zone Growlithe -- Route 201, 202 Elekid -- Route 204 South, Powerplant

LeafGreen Weedle -- Route 204 South Kakuna -- Hakutai Forest Sandshrew -- Lost Cave Sandslash -- Route 228 Vulpix -- Route 209 Magby -- Hard Mountain, Route 227

Any Pokemon GBA Cartridge Haunter -- Forest Mansion Gengar -- Forest Mansion Room with eyes