As the subject states please provide your list of the top 3 best grappling classes (archetypes allowed as well). This would be in terms of strictly locking down your foe and killing them.
1. monk
2. brawler
3. barbarian
Tetori monk
Summoner w/ grab focused eidolon
Wild Shaped druid
Monk
Cavalier with Order of the Penitent (doesn't typically kill, but goes straight from grappled -> tied up with no penalty on the check)
Dip-heavy ridiculous characters that pick up all of the bonuses in all the land (3 levels of Lore Warden, for example)
1. Rage cycling, strength surge barbarian (Pretty much a guaranteed initiation)
2. Tetori halfling monk (Good at initiation and almost impossible to escape from)
3. Druid (Many options, many, many options for grappling. Most damage from grappling too.)
Good mentions here, yeah. The tetori has the best counters to grappling counters like teleportation and such. But I think Lore Warden is king of high CMB, with Barbarian coming in second and limited ability to be the best with strength surge.
One other caveat is Barbarians are really good at tearing people apart in a grapple and using their bodies as weapons against others. Animal Fury, Raging Grappler, Spiked Armor, Body Bludgeon, and Strength Surge is pretty insane.
I've always found lore warden CMB to be a bit overkill, just strength surge is way more than enough to grapple most things that can be reasonably fought as a martial character.