Well, the Skirmisher staff has finally managed to agree upon our "Top 10" selections of our favorite Nemesis cards. Naturally, there is a certain amount of subjectivity in a list like this, and we welcome retorts from readers and are glad to post their top selections. Our selections are also based on a cost-to-benefit ration (i.e., a common card that is profoundly useful rates better with us than a rare card that has potentially useful but highly specialized or esoteric capabilities).
Some of our choices ended up overlapping with those listed in Top Deck, but we did have some marked differences of opinion on certain cards. Indeed, one of their top picks even ended up on our "What the Hell ... ?" list.

Ascendant Evincar (black creature): Well, he isn't cheap (KK+4), but once in play this 3/3 flying creature can turn a pack of black creatures into an iron legion and single-handedly degrade the ability of non-black decks to oppose them. You will, of course, want to find some way to protect him, or else something like a 3-point Thunderclap will knock him out of the game. (Readers have sent in a number of questions about this card, which we have addressed in our Nemesis Question-and-Answer section).

Blinding Angel (white creature): She isn't cheap either, but whenever this angel damages your opponent, he has to skip his next combat phase. This capability could give you an edge over a wife variety of decks, and could permanently lock down an opponent that isn't adequately prepared to deal with flying creatures. And at 2/4, she can both inflict and little bit of damage and resist a wide variety of creature control effects.

Flowstone Slide (red sorcery): Red has a lot to offer in Nemesis, so this might seem like a strange choice to make ahead of so many Laccoliths, Flowstone creatures, and neat spells. Flowstone Slide can give you a lot of options however, and enable you to pump your army just enough to roll over your opponent when the opportunity presents itself or to eradicate unblockable blockers with protection from red (which is notwithstanding against this spell, because it does not target and does not inflict damage).

Lin Sivvi, Defiant Hero (white creature): If you play a Rebel deck, this has just become the most critical card in your deck. Lin Sivvi can be summoned for a mere WW+1 mana, so you can get her on the table by turn two if you play a Remote Farm on your first turn. She can then summon any rebel in your deck for X mana, where is equal to the amount of converted mana needed to summon it. As a 1/3 creature, you are not likely to want to use her as an attacker rather than a recruiter, and she has a bit of resistance to creature-control effects.

Predator, Flagship (artifact): This artifact can give any of your creatures flying (for 2 mana each), destroy a target flying creature (for 5 mana, plus tapping), and, if you have the resources to pull it off, can give an enemy creature flying and then destroy it (for a total of 7 mana). It also has some of the coolest art in the Nemesis set. Recently, I turned a black mercenary deck into an airborne unit with one of these, and managed to shoot up a number of slick Dojo decks with it. A very versatile and promising card.

Rackling (artifact creature): Used in conjunction with discard effects, this artifact creature can quickly rack up telling damage against your opponents (a handful of these along with some Ravenous Rats and spells like Duress can make your opponent look forward to some pain every time he removes a card from his depleted hand). And, as 2/2 creature, the Rackling can also be used as a combatant.

Rathi Intimidator (black creature): With a summoning cost of 1KK, there is a good chance of getting this mercenary recruiter into play on turn one and for it to be summoning other mercs, at a cost of 2, on turn two. Furthermore, it can only be blocked by artifact and black creatures and can be used to inflict some game-turning balance. And, as a common, even the most frugal player can load up a deck with them.

Rising Waters (blue enchantment): Replicating the effects of the old Winter Orb, this spell prevents players from untapping more than one land each turn. While this applies to the caster too, it can buy blue decks the time they need to work by slowing down faster enemy decks. Used in a deck well equipped with non-land mana generators or effects that can untap the caster's land (e.g., the new Trickster Mage), this spell becomes even less of an impediment to its own user.

Rootwater Thief (blue creature): If this was just a 1/2 creature for B+1 that could be gained flying until the end of the turn for B, it would be a good card. However, any time it damages an opponent its owner can pay 2 mana to search his opponent's deck for a card and remove it from the game. This could wreck--and very early in the game, too--decks whose success hinges on a few critical cards. It can also give you critical insight into an opponent's deck.

Skyshroud Behemoth (green creature): Well, there are better players than us who will probably decry our selection of this monstrosity, especially because it comes into play tapped and with only two fading counters. We just can't help but like this gruesome-looking, 10/10 green beast. There are also many ways to keep the Behemoth in play, including the Parallax Inhibitor card-accessory; anything that can return it to your hand for resummoning before it leaves play; and the many means of retrieving green cards from graveyards. "Breakdown," one of the Nemesis preconstructed decks, includes a Behemoth and provides many of these assists for it.