Plethoric lung field is seen in which CHD –
Plethoric lung fields → If the pulmonary blood flow is increased, the lung fields appear plethoric throughout and in addition cardiomegaly is present.
Oligenic lung fields → If the pulmonary blood flow is diminished there is paradoxical prominence of hilar arteries with clear or ischemic peripheral lung fields.

CHDs with plethoric lung fields Cyanotic

Truncus arteriosus
Single ventricle
TGA
TAPVR
Hyperplastic It. heart

Acyanotic

VSD
ASD
PDA

CHDs with oligemic lung fields Cyanotic

Tricuspid atresia
Eisenmenger's syndrome
Ebstein's anomaly
Truncus arteriosus with hypoplastic pulmonary artery
Single ventricle with PS

Acyanotic

As or AR
Coarctation of aorta
MR or MS
PS
Ebstein's anomaly
Tricuspid atresia
AS
VSD