My favorite card of all time? That's a tough one. I'll pick Fireball.
Fireball led to some of the craziest wins I've ever had in multiplayer magic. I remember being in junior high and forking a 10 point fireball to kill 2 people, out of nowhere. I've built multiple decks in different eras of magic's history that utilized fireball as finishers, a 5-color Bringer/cloudpost deck and a R/G Rampaging Baloth deck spring to mind.
I love the flexibility, the power, and the name. It's a Fireball. I win.
It would make a great uncommon for red, as a rare, I think its kinda lame. To use a color-wheel analogy, Counterspell was originally uncommon, then common, then 'too-powerful' and banned. Generally we get overcosted counterspells at common, overcosted counterspells at uncommon that do something, and overcosted counterspells at rare that do something amazing (Time Stop moreso than Last Word). Lightning Bolt was common, then 'too-powerful' and banned. Replaced by Shock at common. Generally we get overcosted burn spells at common, Xburn at uncommon, and overcosted, but potentially devastating burn at rare (Searing Wind, Urza's Rage, Inferno, etc).
Especially compared to something like Lightning Blast or the original Psionic Blast, I think Char would be an excellent uncommon. As a rare, I find it more irritating than anything since if you run Char, you will want to run 4, so you need 4 or none. Sligh and mono-red need as much consistency as possible (though it is splashable burn).
Overall, its > Lightning Blast or Shock, and = Lightning Helix. It just shoulda been uncommon.
Technik
-Anthem and Zealot with Swiftblade-
2 Plains, 1 Mountain, Hound, Swiftblade, Anthem, Zealot. Drawing: Helix, Mountain, Shock.
1st: Plains, Hound
2nd: Draw: Helix. Attack for 2. Mountain, Swiftblade.
3rd: Draw: Mountain. Plains, Anthem. Attack for 7.
4th: Draw: Shock. Mountain, Zealot. Attack 14. -23
-Anthem Kill with Swiftblade-
2 Plains, 1 Mountain, Savannah Lions, Swiftblade, Legionaire, Lightning Helix. Drawing: Anthem, Foundry, Shock.
1st: Plains, Savannah
2nd: Draw Anthem. Attack 2, Mountain, Swiftblade.
3rd: Draw Foundry. Plains, Anthem, Attack 7.
4th: Draw Shock. Foundry, Skyknight Legionaire, Attack 10, Shock for 2. -21
-Zealot Kill with Swiftblade-
2 Plains, 1 Mountain, Lion, Swiftblade, Legionaire, Zealot. Drawing: Shock, Foundry, Helix.
1st: Plains, Lion
2nd: Draw Shock. Attack 2, Mountain, Swiftblade.
3rd: Draw Foundry. Plains, Legionaire, Attack 6.
4th: Draw Helix. Foundry, Zealot, Attack 13. -21.
-Zealot Kill without Swiftblade-
2 Mountain, 1 Plains, Lions x2, Shock, Zealot. Drawing: Hammer, Hawk, Plains.
1st: Plains, Lion.
2nd: Draw Hammer. Attack 2, Mountain, Lion, Shock for 2.
3rd: Draw Hawk. Attack 4. Mountain, Hawk, Hammer for 3.
4th: Draw Plains. Plains, Zealot, Attack 11. -22.
-Anthem Kill Without Swiftblade-
2 Plains, 1 Mountain, Anthemx2, Lionx2. Drawing: Shock, Shock, Mountain.
1st: Plains, Lion.
2nd: Draw Shock. Attack 2, Mountain, Lion, Shock for 2.
3rd: Draw Shock. Plains, Anthem, Attack 6.
4th: Draw Mountain. Mountain, Anthem, Attack 8. Shock for 2. -20.
Thus: If you are going for 4th turn Goldfish with R/W you need a lions or hound on opening draw, period. For finishers, you need zealot or anthem and if you don't have a swiftblade you need multiple lions/hound.
Conclusion: For fishbowling, 4 Lions, 4 Hounds, and 4 Shocks are necessary as openers/fillers. Volcanic Hammer and Lightning Helix are also early fillers if you don't have a two-drop. Intermediaries are Swiftblade and Legionaire, while finishers are Anthem and Zealot. Both anthem and zealot require double mana, one red, one white. On 5th turn and beyond the zealot can accelerate a hound or swiftblade with haste and +1/+1, making a nice surprise finish possible. Another possible finisher is Rally the Righteous which affects all creatures if cast on a R/W, gives +2/+0 and untaps them.
Zealous Anthem 1.0
-1-
4 Isamaru, Hound (R)
4 Savannah Lion (R)
-2-
4 Boros Swiftblade (U)
4 Leonin Skyhunter (U)
-3-
4 Skyknight Legionaire (C)
-4-
4 Flame-kin Zealot (U?)
-1-
4 Shock (C)
-2-
4 Volcanic Hammer (C)
4 Lightning Helix (U)
-3-
4 Glorious Anthem (R)
4 Newduals
4 Painlands
6 Mountain
6 Plains
SB:
4 Hokori
4 Heirophant
4 Disrupting Enchantment
3 Char
Skyhunter has evasion which makes it the last piece. Since this was designed to fishbowl frequently by 4th turn, this is only a prototype. Further, since the shock will probably hit a birds/elder and a helix/hammer may have to clear the way on turn 2, this deck should reasonably win by 5/6 with minimal disruption against it. It doesn't run jittes or artifacts so that is dead in their hand and only 4 enchantments. Hawks and Kami may be better than Hound/Lion, that will take playtesting, the point of the deck is to exploit haste, weenie hordes, and 'anthem-like' effects as quickly as possible.
Technik
4 (W) Suntail Hawk
4 (W) Lantern Kami
4 (RW) Boros Swiftblade
4 (WW) Leonin Skyknight
4 (1RW) Skyknight Legionaire
4 (R) Shock
2 (1R) Volcanic Hammer
4 (RW) Lightning Helix
4 (2R) Char (R)
2 (3) Sunforger (R)
4 (1WW) Glorious Anthem (R)
4 (R/W NewDual) Sacred Foundry (R)
4 Sunhome (Doublestrike land) (R)
7 Plains (Anthem and the 1-drops, not to mention Leonin Skyhunter)
5 Mountains
Sideboard: TBD
Possibly:
4 (1RRW) Flame-kin Zealot 3/3 Haste, gives +1/+1 and haste to all [could be a nice finisher, depending on how prevalent wrath-effects are...]
4 (1RW) Rally the Righteous +2/+0 and untap target, but Radiance [reminiscent of Army of Allah for you old-timers like me]
4 (RW) Trumpeter 2/1 T: can stop attacker or blocker
X (3) Sunforger +4/+0
I love R/W weenie decks, I think most people aren't playing enough burn or fliers, this build has 16 fliers and 14 burn. Also, pay attention to your curves - weenie should have minimum 8 first-turn spells (12 is better) and at least 12 spells for 2-mana (16 or 20 is much better). I eschew jitte because there is so much hate for it you won't get more than 1 or 2 activations. Better to have a burn spell you can clear for the swiftblade or take it to the head.
Stay in the sky and don't get bogged down with combat tricks. Attack and burn, attack and burn.
Technik