As i have read in some blogs these days because of TV serials and movies. The great Pandavas are considered as cowards and evil souls like Duryodhana and Karna are considered as great men. Bhima is shown as a fat, greedy and short tempered warrior.
But Bhima is not as such. Bhima is the second hero of Mahabharata after Arjuna. He is extremely strong and is not afraid of anyone. He defeated Karna many times during Mahabharata war and forced him to retreat chariotless. Karna once defeated Bhima by hiding in his chariot. On 17th day of Mahabharata war Karna insulted Yudhistira. Then Bhima vowed to kill Karna. Bhima fought with Karna and made him unconscious. He was about to cut of the tongue of Karna but Shalya stopped him and told him Arjuna has vowed to kill Karna so leave him. Thus Bhima spared Karna. In TV serials they did not show this scene. This is available in Mahabharata translation by Kisan Mohan Ganguli.
Comparing Bhima and Duryodhana. Bhima was much stronger than Duryodhana but Duryodhana has more skill in mace than Bhima. Bhima is the protector of remaining pandavas including Arjuna during burning of wax house.