Here is my choices:

Mushroom Men: $29.87 at a store nearby

Elebits: $10

That is all I got so far need some help.  No More Heroes got pretty good reviews, but I don't think it looks that great from the gameplay footage i've seen.  Super Mario Galaxy is always at a minimum $45, but my budget is $30.  Please help a brother out.

No More Heroes.
I don't care if you don't like it :P It's awesome ;)

Of the 2 choices you gave I would go with Mushroom men. It just looks like a very fun game.

Other than that, I would say No More Heroes, I also heard that game was awesome.

If you are willing to wait I think they have a "No More Heroes + Red Steel" dual-pack coming out for $29.99. If you don't have Red Steel of course.

No More Heroes is a fun game, flawed and slightly repetitive and not everyone's cup of tea. Awesome boss battles though.

Elebits is a light-hearted fun game where you use whats basically a Ghostbusters proton energy pack to move furniture, find elebits and blast them. I owned it and thought it was 'meh' but had a friend that loved it to death (too bad he didn't have his own Wii so I could get him out of my living room). Good for playing with your wife (and kids if you have).

Mushroom is a solid but not stellar 3d platformer. Good deal at $30.

Of those two, I've only played Elebits.

So I recommend Mushroom Men.

Outside of that.... if it has to be today?

How much is Zack and Wiki? I bet you can find it used for cheap.

it would be shame if you wouldn't pick up elebits especially if you can get them for 10$ - really great game, innovative and fun. i'm still playing this from time to time.
besides this is the only konami game worth playing except PES2008 and Dewy's adventure on wii.
wait you don't have no more heroes yet? buy one. maybe it's not best one on videos, but it really shines while playing.
overall i would recommend buying first elebits(it's great game and pretty hard to find sometimes) especially for such low price and later NMH.

No More Heroes is an amazing game.

Madworld? Tenchu? Deadly Creatures? Dead Rising? The House of the Dead: Overkill?

I suggest Pikmin if you haven't played it before. Its $29.99 and well worth it.

Elebits is a great game, I recommend it