~*Ark*~
Hit Points: 18
Weapon: 5-10* (Broadsword)
Armor: 5-9
Strength: 5
Defense: 5
Speed: 5
Weight: 5
~*Ivy*~
Hit Points: 16
Weapon: 4-9* (Handgun)
Armor: 4-8
Strength: 4
Defense: 4
Speed: 5
Weight: 3
~*Vanrose*~
Hit Points: 20
Weapon: 6-10 (Ninja Edge)
Armor: 5-9
Strength: 6
Defense: 5
Speed: 6
Weight: 5
~*Shelley*~
Hit Points: 14
Weapon: 4-8 (Rifle)
Armor: 4-8
Strength: 4
Defense: 4
Speed: 5
Weight: 3
~*Claude*~
Hit Points: 14
Weapon: N/A
Armor: 5-9
Strength: 4
Defense: 5
Speed: 5
Weight: 5
~*Doug*~
Hit Points: 16
Weapon: 4-8 (Hammer)
Armor: 5-9
Strength: 4
Defense: 5
Speed: 3
Weight: 5
~*Ileyda*~
Hit Points: 12
Weapon: N/A
Armor: 2-6
Strength: 2
Defense: 2
Speed: 3
Weight: 3
~*Philis*~
Hit Points: 12
Weapon: N/A
Armor: 3-7
Strength: 3
Defense: 3
Speed: 5
Weight: 3
~*Telmia*~
Hit Points: 12
Weapon: N/A
Armor: 2-6
Strength: 2
Defense: 2
Speed: 4
Weight: 3
~*Rick*~
Hit Points: 16
Weapon: 4-8 (Magic Wand)
Armor: 4-8
Strength: 4
Defense: 4
Speed: 5
Weight: 5
~*Diana*~
Hit Points: 14
Weapon: N/A
Armor: 3-7
Strength: 4
Defense: 3
Speed: 6
Weight: 3
~*Yurald*~
Hit Points: 14
Weapon: N/A
Armor: 3-7
Strength: 3
Defense: 3
Speed: 4
Weight: 5
~*Jean*~
Hit Points: 16
Weapon: 4-8 (Throwing Knives Scalpels)
Armor: 4-8
Strength: 4
Defense: 4
Speed: 4
Weight: 5
~*Eberle*~
Hit Points: 14
Weapon: N/A
Armor: 3-7
Strength: 3
Defense: 3
Speed: 4
Weight: 3
~*Halley*~
Hit Points: 12
Weapon: 3-7 (Slingshot)
Armor: 4-8
Strength: 3
Defense: 4
Speed: 6
Weight: 1
~*Emmy*~
Hit Points: 10
Weapon: N/A
Armor: 2-6
Strength: 1
Defense: 2
Speed: 5
Weight: 1
*There is no canonically explained reason why Ark and Ivy get two points instead of one in their last upgrade. My guess would be that Doug is putting something extra special in their final customization, either seeing as Elizabeth was just avenged when it became available or to make up for the shit he put them through as Gate Guardians. Probably the latter since it's still available if you beat more dungeons and Doug's happy high over Falcken's defeat has had time to wear off.
Ranking each of the characters in order from best to worst in each stat sans weight (there is no best and worst since you need different amounts for different things, plus it's determined by age and gender rather than character).
~*Hit Points*~
Vanrose (20)
Ark (18)
Ivy, Doug, Rick, Jean (16)
Shelley, Diana, Yurald, Eberle (14)
Ileyda, Philis, Telmia, Halley (12)
Emmy (10)
~*Weapon*~
Vanrose (6-10)
Ark (5-10)
Ivy (4-9)
Shelley, Doug, Rick, Jean (4-8)
Halley (3-7)
~*Armor*~
Ark, Vanrose, Claude, Doug (5-9)
Ivy, Shelley, Rick, Jean, Halley (4-8)
Philis, Diana, Yurald, Eberle (3-7)
Ileyda, Telmia, Emmy (2-6)
~*Attack*~
Vanrose (6)
Ark (5)
Ivy, Shelley, Claude, Doug, Rick, Diana, Jean (4)
Philis, Yurald, Eberle, Halley (3)
Ileyda, Telmia (2)
Emmy (1)
~*Defense*~
Ark, Vanrose, Claude, Doug (5)
Ivy, Shelley, Rick, Jean, Halley (4)
Philis, Diana, Yurald, Eberle (3)
Ileyda, Telmia, Emmy (2)
~*Speed*~
Vanrose, Diana, Halley (6)
Ark, Ivy, Shelley, Claude, Philis, Rick, Emmy (5)
Telmia, Yurald, Jean, Eberle (4)
Doug, Ileyda (3)
Statwise, Emmy is worst in everything sans speed (fitting for an eight-year-old so it doesn't seem so out of place), so extra care is needed for protecting her. Though you can throw Telmia and Ileyda into that mix, because they don't have that much more HP, have less speed (especially Ileyda) and the only other stat they're better at her in is Attack (which is useless on non-fighting characters). Unfortunately, protecting Emmy isn't always the easiest thing due to broken bridges...but for some reason the other two's death count far outweighs hers whenever I play (sad, considering they join much later).
As for the best, it's Vanrose hands down. He's got more HP, speed and attack than Ark, though Ark equals him in weapon strength during the last upgrade, and equal defensive abilities. Not only that, but his power attack involves sending out a shockwave whereas Ark's just slashes twice, meaning Vanrose is able to attack from a farther distance away; it was even incorporated into a puzzle in the final dungeon.