I am mainly looking for some hidden gems. Everone knows games like Megaman, Castlevania, Turtles, Contra etc... But what hidden gems are there out there that i should get?

Anything by Konami/Ultra is a safe bet...although they did produce a couple less-than-stellar titles, most of their games are at least decent, if not awesome.  Aside from that, Vice Project Doom, Dr. Chaos, Dick Tracy, Astyanax, City Connection, Rygar, Rolling Thunder, and a bunch of others that I'm too lazy to recall   Taito also had a ton of great games, especially some of their late-release stuff.

One of my favorite hidden gems for the NES is Solomon's Key.

-Dain

every title suggested is weak here,these Nintendoage "pokemon,got'a catch'em all" collectors have no idea what a "good" game is and over embellish the terms "gem" or "rare"
you want a good rare nes game get metal-storm, isolated warriors (not that rare,but gem!) thats off the top of my head terrea-cresta rocks too along with image fight,ive noticed "irem" games are well programed and a good company like konami for nes games!

that not a "nintendo game" knock-offs dont count as collectibles,he wants gems not turds lol j/k man im feisty this morning

Right now NES is anybodys game. The carts are super easy to break, and Most are not in great condition. One day Nintendo is going to do what we never expect. Bring back the NES original type, and people will be racing around the world, to get those games for that system. That is the heads up.

It will be like the day when congress bann Discs and brings back VHS. Seriously dude,

homebrewed games seems to be attraction, as well.

I agree... Jackie Chan, Metal Storm, Rygar, and Isolated Warrior are very fun games.  Personally, I like Snake's Revenge better than Metal Gear, but that's just my opinion. 

First off, for someone who just started collecting...I wouldn't search for Little Samson, Fire N Ice, and Snow Brothers.  I'm guessing that was a joke??

Most Capcom and Konami games are pretty good.  For instance, I really like Jackal and Life Force (Konami).  Likewise, I think Code Name: Viper and Street Fighter 2010 are cool games (Capcom). 

You know what game is AWESOME?  Guerilla War!  That might be one of my favorite games of all time.  Other great games include Batman, Journey to Silius, River City Ransom, and Power Blade. 

Boulder Dash is fun too!

Your purpose for this post was to inquire about "hidden gems," but hopefully you'll spend time collecting the classics.  They're popular for a reason!  Your money is well-spent on games like Double Dragon, Mega Man, Contra, Ninja Gaiden, Duck Tales, Rescue Rangers, and Mike Tyson's Punch Out.

Just don't buy games like Super Pitfall, Dragon Power, or Deadly Towers. 

I think it's funny how people like Astyanax.  Christmas of 1990, my parents bought me that game (along with Demon Sword and Strider).  I played Astyanax til my thumbs were sore, and looking back now, that game kinda sucks.  The controls aren't great.  You're a huge target.  The enemies knock you all over the screen.  (Sigh) but I still have an attachment to that game.  Why couldn't my parents buy me a cooler game like TMNT 2?? 

Didn't you hate that?  When all of your other friends got cool games for Christmas, and you got some discount game that made you bang your head against the wall, but you played it 24-7 anyway because that's all you had?  Yea...that was me at 8-yrs old.  My friends got Rescue Rangers and Ninja Gaiden 2.  I got Astyanax.