Type: Normal Magic
Effect:  Each player takes 1 Monster Card from his/her respective Graveyard and Special Summons them on the field in face-down Defense Position.
 
 
 
 

Pros
The Shallow Grave is a useful card for getting back some flip effect monsters.  You can reuse Magician of Faith or Man-Eater Bug, or you can just get something powerful and flip it next turn.  Another way to bring back monsters from the Graveyard is always nice.

Cons
Your opponent gets a monster too.  That pretty much says it all right there.  All they have to do is get a Man-Eater Bug, and since they'll get the first chance to flip, you may end up wasting a card.  Also, some decks, such as direct damage and deck destruction decks, rely heavily on their flip effects, and giving them a flip effect back may kill you. Use with caution.

Combos
Soul Release + Shallow Grave - clear out the monsters you don't want your opponent to have, then get one of your monsters
    back
Shallow Grave + monster removal - get back a monster and kill the one your opponent gets

Rating: 2.9/5
It's okay, but you really need the right circumstances for this card to be useful.

Pros
Use it to get back your own effect monsters. If you run a deck that relies heavily on Monster Effects, this card is a good one to add. It works great for Exodia.

Cons
You're not the only one to get the effect. Your opponent get a free monster, and the first chance to flip it. If they have no monsters in their graveyard, then you're set, but how often does that happen?

Combos
Shallow Grave + Spellbinding Circle ( I don't like Spellbinding Circle, but it works )
Shallow Grave + Witch of the Black Forest or Sangan

Rating: 2.3/5
Awesome against a monsterless deck, if you can find someone that has one. Not so good against a lot of other decks.