Chunk albacore tuna, packed in water.
Drain water well. Mix with mayo, onions bits, celery bits. Salt and pepper. Serve on any kind of bread with tomato slice and swiss cheese. Can also be eaten with saltines. Mmmm.
[sub]goes to make a sandwich[/sub]
I usually go with the classic
-tuna
-hellmans
but sometimes add (not at the same time)
diced celery
diced tomato
pickle relish or diced dill pickle
hardboiled egg
thousand island dressing
grated cheddar
Not to mention
poor white trash tuna fish:
-tuna
-Lots of miracle whip
-Oyster crackers
(relish optional)
Mix, refrigerate overnight so the crackers can mysteriously absorb the tuna goodness.
Actually quite tasty. Or substitute mayo and you have mock white trash tuna. Yum!
Malt vinegar.
Anything else is gilding the lily. 
It’s not what you put in tuna fish.
It’s what you put the tuna fish in.
I prefer to put it in the trash bin.
I’ve always used a fairly standard mix of mayo, pickle relish, a hard boiled egg, and some spicy mustard. In college, my friends termed this “Tuna Gut-Slap”, after a meal they would push back from the table and slap their guts, proclaiming the meal to be great, etc. Once, I was out of mustard, but had some Japanese Wasabi. I threw in a large dose of that sinus-clearing stuff. The resultant concotion was subsequently called “Tuna Stun” for the effect it had on people after the first bite.
A little bit of Thai fish sauce in tuna gives a flavor reminiscent (at least for me) of those tuna sandwiches my mom made me for lunch when I was in elementary school. (She made them the night before, they sat in the fridge all night, an hour on the bus and then 3 or four hours before lunch in school). It’s actually not bad.
Curry powder in tuna (I mix it with the mayo first) is also good.
Yes! Curry is excellent in tuna.
And by the way, for those of you who eat it, Miracle Whip is in the same phlegm family as oysters and tofu. No snotlike products for me, thanks.
If your tofu is phlegmy, it’s been sitting in the grocery store wayyy too long. That’s horrible just to think about. No wonder some folks don’t like tofu!
I do a pretty standard tuna:
chunk light tuna packed in broth (most tuna labeled as packed in water is actually packed in broth – at least, it is in my grocery stores)
A spoonful or so of mayonnaise (NOT a ton of mayonnaise–it’s a binder, not a staple)
A wee bit of chopped celery if we have any, and we usually don’t
Spicy mustard
Pepper
Finely chopped homemade pickled red onions, the secret ingredient
There’s a place in Chapel Hill, NC called the Skylight Exchange, however, that makes the best damned tuna I’ve ever had. They call it “African Tuna,” and it’s spicy and rich and magnificent. If anyone can help me replicate it (I’ve tried and failed for years), I’ll be eternally grateful.
Daniel
I eat it plain, from the can, packed in olive oil only…fairly well drained.
Also being from a poor Southern family, this is how I learned to make it from my mom and grandma:
Spread liberally on toasted, mayo-d white bread. Mmmm. Now I have to stop at the store and buy tuna on the way home…
Why, because I feed my tuna fish. Sardines are usually cheapest, or smelt, in season (though he gives me ugly looks because the smelt are fresh-water).
They’re carnivores, ya know. Before they were fished so heavily (say, 50 years ago), much of a catch would be huge. A 500 pound tuna was not unusual.
Okay, <sigh> I’ve had my fun.
Recipe:
Yes, tuna is not the dominant ingredient - except in taste. 
My appetite began a gradual decrease in my early 30s. At this point, I probably eat less than half the amount of food I ate at 20, which is a Good Thing.
These days I usually eat it on crackers (Red Oval cracked wheat saltines - but I get the “reduced” salt variant, which has a blue oval on the box). 
I also like tuna salad (not fish) :wally on toast - rye or whole wheat. When on (toasted or not) bread, I also put a very thin coat of Miracle Whip on the bread.
That’s ridiculous; everyone knows you can’t tuna fish. Well, you can tuna fish, but you can’t tuna fish. You can smoke fish, but they’re hard to light.
[some comedian]Ever notice how Americans call it tunafish? It’s like, we just call it tuna, we assume it’ll be fish [/some comedian]
1 can tuna, drained and water given to cat.
Healthy dose of Miracle Whip.
Paprika and onion powder.
Bread.
A Mod said of Carnivorous Plant’s thread:
My Life is Complete.
I agree with TVeblen. People should be flexible, and they might like something even better than their own recipe. I’m willing to try every recipe given so far, except the ones with apples. I’m sorry, but apples just don’t belong in tuna salad.
Also, try adding a couple of drops of Tabasco to your recipes. Trust me.
I vividly remember Dad putting apples in a tuna sandwich when I came home from school for lunch. The crisp, sweet flavor vs the stinky, nasty “oh no don’t make me eat that again” mushy tuna.
Just a little mayo; no other ingredients necessary. (Tuna is actually the only thing I will eat with mayo. )
[slight hijack] A woman I work with has a family recipe for “cheese salad,” which is ground up cheddar cheese with mayo, relish, and onions. She brings it in every Christmas, and everyone loves it. I seem to be the only one who thinks it’s vile. [end slight hijack]
Tuna in Water
Mayo
a touch of mustard
Garlic Salt
Lemon Pepper
Black Pepper
mmmmm
Hm,
<evil grin> OP didn’t specify canned or fresh…why does everybody assume canned?
Fresh tuna, sushi grade - raw as sashimi, with pickled ginger and wasabi and a whole umeboshi on the side
Fresh tuna, self fished or bought at a reputable fishmongers - All depends on my mood.
Cut into 1 inch chunks, marinated in soy with a touch of wasabi and light nontoasted sesame oil, and skewered and grilled lightly. Serve with dipping sauce of marinade, and a side dish of khichri sprinkled with golden fried onions and sesame seeds [http://www.daviddfriedman.com/Medieval/miscellany_pdf/Miscellany.htm the recipe is in here, basically rice and mung beans dressed with butter - or email me for the recipe=)
Cut into nice fillets and marinated in a homemade equivalent to something like a zesty italian dressing, then grilled over a charcoal fire and served with traditional picnic sides of potato salad, cole slaw and homemade watermelon slushy ice for dessert.
Cut into nice fillets and poached in a court bouillion, served with baby peas and a salad dy Berry [more or less cauliflower and a vinaigrette dressing with watercress and radsh roses]
Canned Tuna - varies
Cold as a fairly typical tuna salad…mayo, celery and onion in very fine dice, larger dice of good kalamata olives, chopped capers on toast points, melba toast or wasa crispbread. Can garnish with black lumpfish caviar=)
Hot - make a batch of egg noodles [I cheat and am lazy, make a batch of spaetzle dough and run it through my spaetzle-hex and cook as normal] and a batch of good homemade veloute sauce [either a veal allemand or a chicken supreme sauce] Drain the water packed tuna well [a nice chunk or whole fillet type] and toss with the noodles in a baking dish along with fresh baby peas [raw] a suitable amount of fine dice celery and onions and pour the sauce over the whole mess to cover. Bake in a slow oven - 1.5 or 300F for about 20 minutes or until bubbling, take it out, dump on a bunch of panko [japanese breadcrumbs] that have been lightly tossed with garlic powder, fresh chopped parsley, freshly grated parmesan cheese and a touch of half sharp paprika in addition to just barely enough melted butter to make a gratin. Put back into the oven on 2.5 or 400F for about 5-7 minutes while you make a tossed salad. Serve up with the salad and fresh bread.