I've been playing MtG for over a decade. The amount of combos and cards that I have knowledge of is sickening.
I built a deck around Chains of Mephistopheles, Anvil of Bogardan, Megrim, and Wheel and Deal. This combo is very complex and makes your opponents have to think a whole lot more than they have to. The deck primarily consists of cards with Madness such as Dark Withering, Psychotic Episode, and Circular Logic. Searching cards like Diabolic Tutor, cards that put cards in my hand like Telling Time, Dark Confidant, and top-deck manipulation with Divining Top.
Combo
3X Chains
3X Anvil
3X Megrim
3X Wheel and Deal
Control
3X Dark Withering
3X Psychotic Episode
3X Circular Logic
3X Counterspell
Utility
3X Telling Time
3X Divining Top
3X Dark Confidant
1X Fact or Fiction
1X Demonic Tutor
1X Mystical Tutor
1X Vampiric Tutor
1X Diabolic Tutor
1X Gifts Ungiven
1X Yawgmoth's Will
1X Sol Ring
Land
4X Polluted Delta
4X Underground Sea
4X Watery Grave
4X Tainted Isle
2X Swamp
1X Lotus Petal
2X Island