Highly preterite:
(At least 95% preterite
(rather than imperfect); number is rank order number from dictionary)
1.decidir to decide
2.publicar to publish
3.eleger to chose, elect
4.contribuir to contribute
5.conquistar to conquer
6.adoptar to adopt
7.introduzir to introduce
8.optar to opt
9.influenciar to influence
10.divulgar to make known
11.fundar to found
12.convocar to summon
13.demitir to resign, quit
14.falecer to pass away
15.salientar to point out
16.herdar to inherit
17.estrear to inaugurate
18.ingressar to enter
19.derrotar to defeat, overthrow
20.comparecer to attend, show up
21.detectar to detect
22.restaurar to restore
23.liberar to release
24.culminar to culminate
25.baptizar to baptize
26.contactar to contact
27.aperfeiçoar to perfect
28.accionar to set in motion
29.abdicar to abdicate
30.actualizar to update
31.fracassar to fail
32.solucionar to solve
33.suicidar to commit suicide
Highly imperfect:
(At least 80% imperfect (rather than preterit); dictionary number)
34.estar to be (change from norm)
35.dever must, to owe
36.parecer to seem
37.precisar to need
38.pretender to plan to, intend
39.morar to live (in or at), dwell
40.depender to depend
41.possuir to possess
42.importar to mind, care
43.costumar to be in the habit of
44.necessitar to need
45.temer to fear
46.visar to have in sight
47.competir to compete
48.aguardar to await
49.desconhecer to ignore, not know
50.convir to be suitable to
51.fumar to smoke
52.arder to burn
53.cheirar to smell
54.assemelhar to be similar to
55.ferver to boil
56.moer to mill, grind
57.flutuar to fluctuate, float
58.vigiar to watch over, oversee
59.englobar to encompass
60.diferir to differ
61.suprir to supply
62.fluir to flow
63.detestar to detest
64.escorrer to trickle, drain, drip
65.carecer to need
66.cozer to cook by boiling