The 'street repairs' card requires the player that draws it to pay the bank $40 per house and $115 per hotel, which is a tough blow to folks who have invested heavily to improve their properties.
The two most potentially disastrous cards are those requiring 'street repairs' and 'general repairs' for all houses or hotels you own. There is the famous 'Get out of Jail Free' card, but there's also the 'Go directly to jail. Both Chance and Community Chest cards can be good or bad. In addition, there are three Community Chest squares and three Chance squares that require players to draw a card.