EDIT: this isn't MINE! I'm flattered you guys think I'm talented enough to come up with it, but this list was actually written by msocasey on Tumblr.

Said is a wonderful word, to be completely honest. Most of the time it functions as an "invisible word" wherein the reader doesn't really notice the use of "said".

Said doesn't have to be used rarely. Especially because when you mix your writing up with "mumbled" or "yelled", the readers are able to visualize a more vivid picture.

However, when used way, way too much (meaning after every form of dialogue) it becomes noticeable and annoying.

Generally, pairing dialogue up with actions and feelings can give the reader a gist of the character's personality, since how we talk reflects who we are/what we believe in (somewhat).

But when you don't want to do that and you think a simple word would do, you don't have to use said. Here's a list of words that you can use alternatively (in past tense):

IN RESPONSE TO
Acknowledged
Answered
Protested
INPUT/JOINT CONVERSATION/ASKED
Added
Implored
Inquired
Insisted
Proposed
Queried
Questioned
Recommended
Testified
GUILT/RELUCTANCE/SORRY
Admitted
Apologized
Conceded
Confessed
Professed
FOR SOMEONE ELSE
Advised
Criticized
Critiqued
Suggested
JUST CHECKING
Affirmed
Agreed
Alleged
Confirmed
LOUD
Announced
Chanted
Cheered
Crowed
Screamed
Shrieked
Shouted
Squealed
Yelled
LEWD/CUTE/SECRET SPY FEEL
Appealed
Disclosed
Groaned
Grunted
Moaned
ANGRY
Argued
Barked
Challenged
Cursed
Fumed
Growled
Hissed
Roared
Swore
SMARTASS
Articulated
Asserted
Assured
Avowed
Claimed
Commanded
Cross-examined
Demanded
Digressed
Directed
Foretold
Instructed
Interrupted
Predicted
Proclaimed
Quoted
Theorized
ASSH*LE
Bellowed
Boasted
Bragged
NERVOUS TRAIN-WRECK
Babbled
Bawled
Mumbled
Sputtered
Stammered
Stuttered
SUAVE
Bargained
Divulged
Disclosed
Exhorted
FIRST OFF
Began
LASTLY
Concluded
Concurred
WEAK
Begged
Blurted
Complained
Cried
Faltered
Fretted
Whined
HAPPY/LOL
Cajoled
Cheered
Congratulated
Exclaimed
Gushed
Jested
Joked
Laughed
Squealed
WEIRDLY HAPPY/EXCITED
Extolled
Jabbered
Raved
BRUH, CHILL
Cautioned
Warned
ACTUALLY YOUR'E WRONG
Chided
Contended
Corrected
Countered
Debated
Elaborated
Objected
Ranted
Retorted
CHILL SAVAGE
Commented
Continued
Observed
Surmised
LISTEN BUDDY
Enunciated
Explained
Elaborated
Hinted
Implied
Lectured
Reiterated
Recited
Reminded
Stressed
BRUH I NEED YOU, YOU NEED ME
Confided
Offered
Urged
FINE
Consented
Decided
FULL OF EMOTIONS
Croaked
Lamented
Pleaded
Pledged
Sobbed
Sympathized
Wailed
Whimpered
JUST SAYING
Declared
Decreed
Mentioned
Noted
Pointed out
Postulated
Speculated
Stated
Told
Vouched
WASN'T ME
Denied
Lied
EVIL SMARTASS
Dictated
Equivocated
Ordered
Reprimanded
Threatened
BORED
Droned
Sighed
QUIET TIME
Echoed
Mumbled
Murmured
Muttered
Uttered
Whispered
DRAMA QUEEN
Exaggerated
Panted
Pleaded
Prayed
Preached
OH SH*T
Gasped
Marveled
Screamed
Screeched
Shouted
Shrieked
Yelped
Yelled
ANNOYED
Grunted
Grumbled
Jeered
Quipped
Scolded
Snapped
Snarled
Sneered
ANNOYING
Heckled
Mocked
Nagged
Teased
I DON'T REALLY CARE BUT WHATEVER
Guessed
Hypothesized
Ventured
I'M DRUNK OR JUST BEING WEIRDLY EXPRESSIVE FOR A POINT/SARCASM
Hooted
Howled
Yowled
Whistled
Whooped
OH YEAH, WHOOPS
Recalled
Recited
Remembered
SURPRISE B*TCH
Revealed
I WONDER
Pondered
Voiced
Wondered
B*TCHY
Tattled
Taunted
Teased
IT SEEMS FAKE BUT OKAY/ACTUALLY FUNNY BUT I DON'T WANNA LAUGH OUT LOUD
Choked
Scoffed
Snickered
Snorted

REMEMBER: There's nothing wrong with said, but this is just to spice up your work.

Source: msocasey on tumblr (I added some more)