* = unlock by beating arcade
^ = unlock by some other method
@ = alternate outfit of another character
# = boss character

T1        T2       T3        (TTT)          T4        T5        T6
========= ======== ========= ============== ========= ========= ========
-------------------------------------------------------------------Mishimas
Heihachi# Heihachi Heihachi* Heihachi Mish. Heihachi# Heihachi* Heihachi
Kazuya    Kazuya#           Kazuya Mishima* Kazuya    Kazuya    Kazuya
Devil^    Devil#             Devil*
          Angel@             Angel@                 | Jimpachi#
-------------------------------------------------------------------extended
Lee*      Lee*               Lee Chaolan*   Lee*      Lee       Lee
                                            Violet@          %LarsAlexanderson
-------------------------------------------------------------------Kazamas
          Jun                Jun Kazama             | Asuka K.  Asuka
                   Jin       Jin Kazama     Jin*      Jin       Jin
                             Unknown#               | DevilJin^ DevilJin
-------------------------------------------------------------------othrBoss
                   Ogre#     Ogre*                              Azazel#
                   Tr. Ogre# True Ogre*                         NANCY-MI847J#
-------------------------------------------------------------------buddies
M.Law     M.Law    F.Law     Forrest Law    MarshallL M.Law     M.Law
Paul      Paul     Paul      Paul Phoenix   Paul      Paul      Paul
-------------------------------------------------------------------Chinese
Wang*     Wang*              Wang Jin Rei*            Wang*     Wang
                   Xiaoyu    Xiaoyu Ling    Xiaoyu    Xiaoyu    Xiaoyu
                                            Miharu@ | Feng Wei  Feng
-------------------------------------------------------------------assassins
Nina      Nina     Nina      Nina Williams  Nina*     Nina      Nina
Anna*     Anna*    Anna*     Anna Williams            Anna*     Anna
-------------------------------------------------------------------cyborgs
Jack      Jack-2   Jack-2@   Jack-2*                  Jack-5    Jack-6
P.Jack*   P.Jack*            P.Jack*
                   GunJack*  GunJack                         | %AlisaBosconvtch
                   Bryan*    Bryan Fury     Bryan*    Bryan     Bryan
-------------------------------------------------------------------ninjas
Yoshi     Yoshi    Yoshi     Yoshimitsu     Yoshi     Yoshi     Yoshi
Kuni*     Kuni* DrBosconovitch^ Kunimitsu*
-------------------------------------------------------------------wrasslers
King      King     King      King           King      King      King
A.King*   A.King*            Armor King              %A.King2   A.King2
                                          CraigMarduk Marduk    Marduk
-------------------------------------------------------------------Changs &c.
Michelle  Michelle           Michelle Chang
                   Julia*    Julia Chang    Julia*    Julia     Julia
Ganryu*   Ganryu*            Ganryu                   Ganryu*   Ganryu
-------------------------------------------------------------------taekwando
          Baek*              Baek Doo San             Baek*     Baek
                   Hwoarang  Hwoarang       Hwoarang  Hwoarang  Hwoarang
-------------------------------------------------------------------law&boxing
          Lei      Lei       Lei Wu Long    Lei*      Lei       Lei
          Bruce*             Bruce Irvin*             Bruce*    Bruce
                                            Steve Fox Steve     Steve
-------------------------------------------------------------------capoeira
                   Eddy      Eddy Gordo     Eddy@     Eddy@     Eddy
                   Tiger@    Tiger@  | ChristieMonteiro ChristieChristie
-------------------------------------------------------------------specialOps
                                                      Raven     Raven
                                                 %SergeiDragunovDragunov
-------------------------------------------------------------------???
                                                  %LiliRochefortLili
                                                                Leo
                                                                Zafina
                                                                MiguelCRojo
                                                                Bob
-------------------------------------------------------------------the zoo
Kuma*     Kuma*    Kuma*     Kuma*          Kuma*     Kuma*     Kuma
                   Panda@    Panda@         Panda@    Panda@    Panda(@
          Roger^ | Gon^    | Roger*                   Roger Jr* RogerJr
          Alex@              Alex@
                   Mokujin*  Mokujin@                 Mokujin*  Mokujin
                             Tetsujin*    | Combot
--------------------------------------------------------------------
18        23       21        34             19        31 %34     40 %42

(Totals don't count alternate-outfit characters)
                              % = T5DarkRessurection or T6BloodlineRebellion


TTT2 notes: damn near everyone, including:
 Miharu (like Xiaoyu), Sebastian (like Lili), Slim Bob (like Bob),
 Dr. Bosconovitch, Unknown