The concept should be fairly self-explanatory, I should think. In case it's not: come up with a time-travel scenario so lame that, if time-travel devices were real (and presumably expensive and heavily restricted), and you heard about that scenario having happened, you would get depressed/angry. "We have real time machines, and THIS is what they're being used for?!"

Inspired by a comment in this thread.

I shall start:
Going back to the 1800s to find an "authentic" recipe for soup (and then not making it because it's too difficult).

See? I set the bar low. Anyone should be able to top that (including me, I hope!). =)

A coffee table.

Go back to 07:00 this morning and not burn my toast.
Use the time machine instead of save scumming.
Go back 3 minutes so I can remember that guy's name.

It would be lame to even use it. It is totally pointless, much like true immortality. Also, immortality exists (*that* jellyfish), time machine, NOT.

Go back in time to see certain movies on the "big screen" in theatre.

Go back in time to see certain retired/deceased Elvis impersonators rather than actually seeing Elvis.

Go back in time to eat at closed restaurant chains.

Go back in time to eat certain discontinued foods such as the Alpine White candy bar, or Nintendo cereal.

Go back in time to buy something on a special sale or deal that hasn't come up since.

I'd go back a few minutes to see what I look like from behind.

Not buying mass effect, especially the third, and dragon age 2?

I did, in fact think of a better one than my original:

Repeatedly pop in on the set of Casablanca during filming, just to "pants" Humphrey Bogart then pop back out again.

EDIT: fixed italics

my coffee is not hot anymore. Time machine needed asap.

Go back in time to sleep with your grandmother to ensure your father (and thus you) will born.

I don't know if that count as "lame", but I think you won for "Ickiest use for a time machine"!

Going back in time to sabotage the time machine project.

You're my grand dad? Cool I never knew him. Did grand ma smells back then too?
You owe me 50 years of Christmas, Easter and birthday gift.

Be careful. A few more answers like that and you may surpass me as being the strangest person in here. :P
AND WAIT A TIC! XD

If you did that, how would you get back? As soon as you sabotaged it the time machine you used to go back would disappear.

Go forward in time to give yourself a message.