All below Pokemon have a catch rate if 255, which is the maximum.
Generation 1
010 Caterpie
013 Weedle
016 Pidgey
019 Rattata
021 Spearow
023 Ekans
027 Sandshrew
041 Zubat
043 Oddish
050 Diglett
052 Meowth
060 Poliwag
069 Bellsprout
074 Geodude
129 Magikarp
Generation 2
161 Sentret
163 Hoothoot
165 Ledyba
167 Spinarak
187 Hoppip
194 Wooper
Generation 3
261 Poochyena
263 Zigzagoon
265 Wurmple
270 Lotad
273 Seedot
285 Shroomish
287 Slakoth
290 Nincada
299 Nosepass
300 Skitty
322 Numel
325 Spoink
327 Spinda
328 Trapinch
333 Swablu
343 Baltoy
349 Feebas
363 Spheal
366 Clamperl
Generation 4
396 Starly
399 Bidoof
401 Kricketot
406 Budew
436 Bronzor
438 Bonsly
Generation 5
504 Patrat
505 Watchog
506 Lillipup
509 Purrloin
519 Pidove
524 Roggenrola
531 Audino
535 Tympole
540 Sewaddle
543 Venipede
556 Maractus
572 Minccino
582 Vanillite
597 Ferroseed
605 Elgyem
Generation 6
659 Bunnelby
661 Fletchling
664 Scatterbug
Generation 7
731 Pikipek
734 Yungoos
736 Grubbin
795 Pheromosa
798 Kartana
Source
