I still buy product to open as that is always fun, but even then I only buy sets I think are ...
In fact the printing of Unholy Heat (and to an extent Solitude) has mostly pushed out cards like Tarmogoyf out of the format, as the removal in the format is now so efficient that creatures either need to be one-mana, so you trade at an even level (Dragons Rage Channeler and Ragavan, Nimble Pilferer), too large to be killed by Unholy Heat (Deaths Shadow and Murktide Regent) or generate immediate value upon being played (Solitude, Fury and Omnath, Locus of Creation)
Time range: As long as you maintain it
Creatures (10) Planeswalkers (2) Lands (20) Spells (28) I know what youre thinking, but trust me, if Im not playing Thing in the Ice, then you certainly shouldnt be playing Thing in the Ice
For me, Cruel Ultimatum and Breach the Multiverse are the best
Rocky Tar Pit