Delving into a huge card pool(I mean real huge)

[r_untouchable]

I don't know where to start looking for good cards in this format
may it be for tutoring,removal,creatures,mana sources,counterspells
and also what colors are good in aggro,control and combo
what cards would you say be the "cream of the crop"

I'm asking for opinion to everyone

[Kadaj]

My suggestion is to look at the decks in the DTB forum. There are cards like Brainstorm, Swords to Plowshares, etc, that are almost ubiquitous. From there you just have to use common sense. If a card has a really powerful effect and is cheap (Example: Lightning Bolt) it's probably pretty good.

[xsockmonkeyx]

Fetches and Duals are ubiquitous, as are basics.
then:
Brainstorm
Swords to Plowshares
Dark Ritual
Force of Will
Tarmogoyf
Thoughtseize
Wasteland
Chalice of the Void
Sensei's Divining Top
Ponder
Tendrils of Agony
Survival of the Fittest
Dark Confidant
Counterbalance
Krosan Grip
Aether Vial
Life from the Loam
Standstill
Daze
Blue Elemental Blast/Hydroblast
Red Elemental Blast/Pyroblast
Tormod's Crypt
Duress
Lightning Bolt
Pithing Needle
Counterspell
Leyline of the Void
Pyroclasm
Stifle
Hymn to Tourach
Mishra's Factory
Pernicious Deed
Lotus Petal
Ancient Tomb
Mox Diamond
Cabal Therapy
Blood Moon/Magus of the Moon
Burning Wish
Empty the Warrens
Spell Snare
Engineered Explosives
Fact or Fiction

[Fossil4182]

I would say that Legacy's card pool and also the need for cards is even larger than Vintage in a lot of ways. I think the best place to start with developing a card pool is deciding what type of deck you want to build. We could all list dozens of cards that are "must haves" but it all really depends on your deck selection. I think the best thing we could do to help you is to find out what your deck selection is and then suggest cards that you ought to be tracking down to start your collection. Ideally, its best to start off focused and build a deck, then use what you have and see what other decks it can be used in and just grow it out.

[Anusien]

If you're looking for cards other people haven't found, pick sets you're not familiar with and look at every card. Especially look at things like The Dark, Antiquities, Legends, and the Portal I-III and Starter. This is how gems like Imperial Recruiter are found.

[TheInfamousBearAssassin]

You can use the MWS search and filter tools to look through lists of relevant cards, although they have a tendency to always miss a few options. It just comes with time and experience.

[r_untouchable]

Is empty the warrens really a good card???

[Nihil Credo]

Is empty the warrens really a good card???

Yes.

[Michael Keller]

Empty the Warrens (even if you only create six tokens first turn off three spells) can be an overwhelming threat if your opponent can't deal with it early enough. They're looking at a four turn clock on that alone. Most storm-based combo decks use at least one copy as a secondary win condition.

In Belcher variants, it's more often than not your primary source for victory.

[TeenieBopper]

Slacker.

[Willoe]

Nihil, which program do you use for this?

[ParkerLewis]

Nihil, which program do you use for this?

That's just MWS.

[r_untouchable]

Yes.

pyroclasm!!

[xsockmonkeyx]

Actually, there are tons of things you can do to kill a bunch of 1/1 tokens. We had a whole thread a while ago discussing it, here.