Aggregate FIFA ranking of all four teams in each group, and lowest ranked team in each group, assuming that the highest ranked team wins in each playoff pathway:
A - 119, South Africa (61)
B - 107, Qatar (51)
C - 136, Haiti (84)
D - 104, Paraguay (39)
E - 156, Curacao (82)
F - 93, Tunisia (40)
G - 148, New Zealand (86)
H - 145, Cape Verde (68)
I - 109, Iraq (58)
J - 127, Jordan (66)
K - 125, DR Congo (56)
L - 116, Ghana (72)
Going just off FIFA rankings (which, just no, don't do that), F is the most competitive and balanced group, and we've got the best worst team in group D.
Aside from weird arbitrary rankings, it's gotta be I. France, Senegal and Norway is just brutal.