1. Dual lands fix mana
Mana screw is really frustrating, and color screw may be even worse. Dual lands (and triple and prismatic ones) contribute to lower the odds of color screw, rewarding players who spent their picks with lands. Another consequence is that decks with more than two colors become much more feasible, reducing the need for mana fixing spells.
2. Nonbasic lands reduce the number of cards left out of the decks.
In regular booster drafts, lots of cards stay out for being unplayable. Except for some linear cards or very late picks not in their colors, in cube drafts players end up with 40ish cards, from which he will have to pick around 23. When you add nonbasic lands to the mixture, you're not limited to picking our 23 spells anymore, but there are 17 slots that can be filled with nonbasics. Of course, each player will have around 2-3 nonbasics for his deck, but that's 2-3 extra cards being played.
3. Nonbasic lands add complexity and decisions to the game.
Playing nonbasics that come into play tapped or deal damage to you or might become attackers require more planning than the regular basic lands without "summoning sickness". Even in the deck construction stage there are new dilemmas - should an aggro deck use taplands of its colors for consistency or just plain basics for speed? Should control decks run City of Brass?
As for which lands cycles to get in a cube, that will depend greatly on your budget.
Revised dual landsTundra, Underground Sea, Badlands, Taiga, Savannah, Scrubland, Bayou, Tropical Island, Volcanic Island, Plateau
- Very expensive.
- Allied and enemy colors.
- Strictly better than most duals.
- Count as the land types for all purposes except they are not considered basic.
- Don't slow you down.
Ravnica bounce landsAzorius Chancery, Dimir Aqueduct, Rakdos Carnarium, Gruul Turf, Selesnya Sanctuary, Orzhov Basilica, Golgari Rot Farm, Simic Growth Chamber, Izzet Boilerworks, Boros Garrison
- Cheap.
- Allied and enemy colors.
- Awkward and slow in the early game.
- Extend your mana reach.
- Great with landfall.
Ravnica shock landsHallowed Fountain, Watery Grave, Blood Crypt, Stomping Ground, Temple Garden, Godless Shrine, Overgrown Tomb, Breeding Pool, Steam Vents, Sacred Foundry
- Average to expensive.
- Allied and enemy colors.
- Count as the land types for all purposes except they are not considered basic.
- Either slow you down or require 2 life payment.
Onslaught/Zendikar fetch landsFlooded Strand, Polluted Delta, Bloodstained Mire, Wooded Foothills, Windswept Heath, Marsh Flats, Verdant Catacombs, Misty Rainforest, Scalding Tarn, Arid Mesa
- Expensive.
- Allied colors from Onslaught, enemy colors from Zendikar.
- Thin the deck.
- Fetch actual basic lands.
- Small life payment.
- Don't slow you down.
- Great with landfall.
Mirage fetch landsFlood Plain, Bad River, Rocky Tar Pit, Mountain Valley, Grasslands
- Cheap.
- Only allied colors.
- Thin the deck.
- Fetch actual basic lands.
- Slow, as they come into play tapped.
- Great with landfall.
Urza manlandsForbidding Watchtower, Faerie Conclave, Spawning Pool, Ghitu Encampment, Treetop Village
- Cheap.
- Monocolored.
- Slow, as they come into play tapped.
- Turn into creatures for 1C.
Worldwake manlandsCelestian Colonnade, Creeping Tar Pit, Lavaclaw Reaches, Raging Ravine, Stirring Wildwood
- Average price.
- Only allied colors.
- Slow, as they come into play tapped.
- Turn into creatures for varying costs, all involving at least one mana of each color produced.
Alara tri landsSeaside Citadel, Arcane Sanctum, Crumbling Necropolis, Savage Lands, Jungle Shrine
- Cheap to average.
- Only allied shards (enemy combinations are called wedges).
- Slow, as they come into play tapped.
- Make three colors instead of the usual two, meaning it's unlikely no one will want them in a draft.
M10 dual landsGlacial Fortress, Drowned Catacomb, Dragonskull Summit, Rootbound Crag, Sunpetal Grove
- Average price.
- Only allied colors.
- Sometimes slow, sometimes fast.
Scars of Mirrodin dual landsSeachrome Coast, Darkslick Shores, Blackcleave Cliffs, Copperline Gorge, Razorverge Thicket
- Average price.
- Only allied colors.
- Fast at the beginning of the game, slow after that.
Alliances replacement landsKjeldoran Outpost, Soldevi Excavations, Lake of the Dead, Balduvian Trading Post, Heart of Yavimaya
- Kjeldoran Outpost and Lake of the Dead are average, the others are cheap.
- Monocolored.
- Lake of the Dead and Heart of Yavimaya slow you down but have more powerful effects. The others don't slow you, but the colorless mana is awkward.
- Good repeatable activated abilities in general.
Shadowmoor filter landsMystic Gate, Sunken Ruins, Graven Cairns, Fire-Lit Thicket, Wooded Bastion, Fetid Heath, Twilight Mire, Flooded Grove, Cascade Bluffs, Rugged Prairie
- Average price.
- Both allied and enemy colors.
- Don't slow you down.
- Good to pay heavy colored costs (see Cloudthresher).
- Can't produce a single colored mana.
Ice Age/Apocalypse pain landsAdarkar Wastes, Underground River, Sulfurous Springs, Karplusan Forest, Brushland, Caves of Koilos, Llanowar Wastes, Yavimaya Coast, Shivan Reef, Battlefield Forge
- Cheap to average price.
- Both allied and enemy colors.
- Don't slow you down.
- Require life to produce colored mana.
Legends legendary landsKarakas, Tolaria, Urborg, Hammerheim, Pendelhaven
- Karakas is very expensive. The others are cheap.
- Monocolored.
- Don't slow you down.
- Legendary, which rarely matters in cube.
- Karakas and Pendelhaven have good abilities. The others are meh to worthless.
Not all lands come in cycles, though. There are lots of others that work well in cube draft:
City of Brass - A must have, even though it's suicidal, it smoothes the mana of any deck and does not compromise speed in any way.
Mystifying Maze - The new Maze of Ith, good for defensive decks.
Mishra's Factory - The first manland, it hurts your colors a bit, but becomes a difficult to kill 2/2 for mere 1 mana.
Grand Coliseum - A slow City of Brass that's not suicidal unless you need it for specific colors. Definitely worse than the City, but still worth playing.
Gemstone Mine - Usually 3 charges will be enough to get your game going until you get the color that's missing. Best in aggro decks, though.
Desert - Makes attacking decisions harder for your opponent, helping agaisnt beatdown.
Quicksand - Same as Desert, only in a different way.
Stalking Stones - Not as good as a Mishra's Factory, but it's a land that doesn't sit dead in the late game.
Strip Mine - Takes some games by itself.
And moving on to the really expensive options:
Undiscovered Paradise - Very bad for mana development, although it makes any mana color the turn it comes into play. Besides, it's awesome with landfall.
Library of Alexandria - Unfair, works like a 1st turn hard to kill Phyrexian Arena.
Mishra's Workshop - May encourage artifact decks by itself
Mutavault - The new Mishra's Factory, except it's a changeling instead of an artifact.
Maze of Ith - Almost not a land, since it doesn't make mana, rather it's like an immortal blocker.
