Mine are swords, orbs, robots, guns.

hiei's black dragon spirit technique.
V2's minovsky drive system.
GP03's dendrobium weapons system.

Mazinger Machines.

Clouds Buster Sword

Demon Guns of Beyond The Grave

Shin Getter Cannon.

Samurai Sword of Himura Kenshin

Latigo ni Louise

Boob Rockets 1 & 2 ni Aphrodite-A

Wave Motion Gun of Space Battleship Yamato

Chest Fire ni Mazinger Z

Saber's Sword of course

the weapons from F/SN

the Valkyries of Macross

Samurai X

Most of my favorites are from video games but here are some anime weapons that caught my eye:

Edward's Automail Blade
Yoh's Harusame and Futsu no Mitama no Tsurugi
Saber's Caliburn and Excalibur
Archer's Falchion (sp?) and Byakuya

Soul Breaker!!! (G)

Shinning finger!!! (GG)

Double Buster riffle (GW EW)

Kamehame wave (DBZ)

nu-gundam's fin funnel
strike freedom's super dragoon
gundam f-91's mouth beam
god gundam sekiha tien ko ken & god finger
mazinkaiser's fireblaster, turbo smasher punch
shin getter's giant tomahwak & scythe

Bleach Soi Fong's Suzumebachi
EVA-00's Lance of Longinus
Hatake Kakashi's Raikiri/Chidori

kenshin's reverse edge shinochiai<sana tama spelling ko> - amakakeru ryu no hirameki!!
Son Gouku's stretch staff
Clow Cards
Kamui's sword
Weapons of the Magic Knight Rayearth Gals
Ray gun
Rose Wipe and some other plant weapons of Kurama

BWAHAHAHAHAHAHA~~!! Been watching Higurashi again...I feel the sensation of killing!!!

Kahit ano basta mga katulad ng weapon ni KOS-MOS.

Guns sa akin and deathnote.

Edward Elric's alchemy hands

Dante's Ebony and Ivory

Alucard's twin guns

Guts' Broad Sword

Knightmare's Soul Calibur

Anything with blades.

weapons???

-gunblade "lionheart" ni squall
-cloud's buster sword
-omega/ultima weapon
-mikuru beam (lolz)
-sakabatou, twin kodachi ---> kenshin & aioshi
-kosmos' twin big guns
-archer's weapons in unlimited blade works
-saber's swords

death note can be considered a weapon coz' it kills!!!

A VF-1S Valk equipped with GBP Armor

The weapon that could cure someone from being an idiot and kick the bottom of everyone if used by a ministra magi...Harisen!!!

Fate Stay Night: Archer's weapon.. yun lng muna

Strike freedom gundam.... ( dapat meron kasama si lacus sa loob..... )

Archer's weapons - i personally like the spell in Engrish! hehehe " I am the bone of my sword..yada yada"
Ichigo's Zangetsu and Byakuya's Senbonzakura from Bleach
Neji's Jyuuken
Neo Armstrong Cyclone Jet Armstrong Cannon from Gintama -'nuff said hahahaha
Sora's Keyblades
all Trigun weapons

Final Fantasy Summons - 9999 damage ehehe

Charge Particle Cannon from Zoids
Moonstone Cannon from Skies of Arcadia

And yeah all powerful Rei Ayanami beach slap >

S.O.L = Stalker Obliterating Laser
Gin's bokuto
all from Gintama
Vampire Hunter D's left arm

Gundam Physallis' Atomic rocket launcher

Sazabi's Twin beam Tomahawk / funnels

TallGeese III's mega cannon / heat whip

GM Sniper's sniper rifle

Double X's twin mega beam particle shoulder mounted cannon

Turn A's moonlight butterfly / twin hammer

Dygenguard's zanpaktou

Nirvana's (Eureka 7) traparr board

Lancer's Gae Bolg

Claire's claymore (although they all look the same)

KENSHIRO'S FISTS

Dio's THE WORLD

Jeeg's twin drill arm

and Sanosuke Sagara's broad sword

-Luffy Gear 2 and 3

-Zoro's Asura Technique

-Haruhi Suzumiya...

-Ichigo's Bankai and Zanpakuto

-Keyblade

-Naruto's Rasengan

-The Kamehameha

-Swords ni Haru Glory

-Cloud's Buster sword

-Raitei Mode ni Ginji

Kamehame Wave (DBZ)

Pag nag papacute ang isang CUUUUTEEEE na char sa anime na halos matunaw ka sa kakyutan! (BWHAHAHAHA ~~~~~diabolic laugh)

Pag pinakitaan ka sa anime ng (bagay na sisirit dugo mo sa ilong) aun na!

Mga newtype abilities sa Gundam (impossible sila tamaan at sila lagi tatama sau! )

LASER SWOOOORDDDDD!!!! (Voltes V, walang tatalo d2!)

Excaliborg pipirupirupipirupiiii!
but i like the Will of haruhi, when she likes it, it happens

Yoko's sniper rifle!!!

and MIKURU BEAM!!!

Dio Brando's Za Warudo
Jotaro Kujo's Star Platinum
Kenshiro and Raoh's North Star Fists
Gatz's Dragon Slayer
Guyver Suits
Kinniku Buster
Vann's Dan Of Thursday
Richard's Daimos

1. Twin Buster Rifle GW (Hindi mo malaman kung saan kinukuha nang Wing Zero yung energy nung baril)

2. Death Note (Patay lahat sila dto wag lang nila malalaman kung sino yung gumagamit)

the Avatar's elements(weapon ba yun?)
no equipping needed!

Nanoha's Raging/Raising Heart Excellion (Star Light Breaker!!!)
Fate's Bardiche Assault
Zengar Zomvolt's Zankatou
God Sigma Gravion's Super Heavyweight Sword
Kyosuke Nanbu's Alt Eisen/Riese weapons: Claymores and Stakes
Arado Balanga's Wild Wurger Weapon: Stag Beetle Crusher
Aquarion's Technique: Mugen PUUUUUUUUUUUUNCH!!!!!!!!
Nirvash Type Zero's Cutback Drop turn
Nanajin's Hyper Aura Giri
The FAZZ's Hyper Mega Cannon
The Nu Gundam's Fin Funnel System
Death Scythe's Beam Scissors

I don't know if it's really a weapon but.. Basara's song "Totsugeki Love Heart!!'" (Well, they are weapons against the Protodevlins...)

Archer's Unlimited Blade works
Saber's Excalibur and Avalon (kung may offense may defense dapat...)
Gilgamesh's Gate of babylon and Enuma Elish
Keroro's kero ball
Ichigo's Bankai
Laevatein/Arbalest's Lambda driver
virgo shaka's tenbu hourin (one of the best techniques created )still, weapon ba'to?
gemini saga/kanon's Galaxian explosion, still don't know if considered a weapon
strike freedom gundam
Keitaro's immortality, weapon pa rin ba'to?
Alucard's crissaegrim
destructive blade Sabrac's stigma
Rinoa's Sorcery, ...dead fantasy rocks!
Reverie Metherlence sword Form
Clannad Tomoyo's Combo kick