We've been "prepping" as a family now for about 14 years or so and I've had several occasions now to eat foods WAY past their expiration dates.
Fortunately we've had more successes than failures.
Tuna 6 years past exp was just fine.
Sardines in oil and water 2-3 years past exp was fine.
I thought that if anything would get me it would be the fish. I was wrong.
Tomato based entrees on the other hand, not my favorite choice for long term.6 months past expiration on Chef Boyardee type stuff and it feels so acidic I thought it would burn the skin off my tongue.
We've had cans of fruits (pineapple jumps to mind) fail after only a few months past exp as evidenced by the can swelling.
On the other hand, we have eaten various and random canned fruits and vegetables as far as 9 years past expiration. Not much of a common theme or brand preference I could point to in this regard OTHER THAN when a can does fail odds are it is the pull tab kind, not the kind you would have to use a can opener to open.
I have eaten Armour Viennas 2 years past expiration and they were fine.
I have eaten Hormel Spam 6 years past exp and it tasted perfect.
Any grain product is subject to infestation while stored, but how you choose to store it can of course negate the chances.
One of my more epic failures early on was oddly enough Ramen noodles as mentioned upstream. We were buying them by the "case" (cardboard flat with heavy plastic on the outside and individually wrapped packs on the inside) and the way they were packaged I guess gave us a false sense that we didn't need to do anything further. Apparently the individual packages are a little permeable. We had stored ours in the root cellar which does by necessity have a small amount of humidity present. After a year we got a flat out and every package was molded when opened. Lesson learned.
By and large, storage conditions and package type seem to affect food longevity way more than age past expiration date.
PS:
I know our pressure canned/home canned goods is whole different topic, but, we have eaten our deer meat (cubed) up to 10 years old. Pickles, jelly/preserves, green beans, and stuff like that we have eaten after 12-14 years with no problem.