I stopped collecting at around exodus, so my knowledge of the newer cards is non-existent.
Still, I loved playing blue control decks. Nothing beats the thrill of slowly but surely capsizing all your opponent's permanents back to his hand (it was funny when I ended up countering his attempts at incinerating his own creatures in a bid to fizzle my buyback spells), while having a hand full of counterspells. Forbid means that I am never without a counterspell, while ophidian/whispers of the muse lets me draw extra cards to fuel my counter-frenzy.
Favourite card interaction? Nature's revolt + Pendrell Mists + Propaganda. All land are creatures, you must pay 1 mana per creature during upkeep or bury it. And you cannot attack unless you pay 2 mana per attacking creature. Meanwhile, I have artifact mana in play, so I eventually win by attacking with a single animated land.
Probably primitive by today's standards, but "revolting mists" was quite fun in its heyday.