Mega Man X4 is the best in that series. The original is the second best.

I'm surprised that no one has mentioned Paper Mario. The original was great, TTYD was a masterpiece, and then it kind of went down hill from there.

I actually never played the original Paper Mario but I sure did enjoy the TTYD, it's one of the few games I actually got my wife to play with me ... what a fun little game!

Good call! I have yet to play TTYD (heard amazing things), but I recently beat the 64 one and loved it, so I'm hoping to get around to the sequel soon. 

I agree that these are the top two in the series,although I'd probably give X1 a very slight edge.They are pretty much 1a and 1b to me. These two also have the best soundtracks.

It was said earlier in this thread and I have to second the opinion because I know its unpopular - Zelda 2 NES is better than Zelda 1.

I find it disgusting that nobody said Resident Evil.

Nevermind, the lazy ass didn't bother spelling it out. Shameful.

Mortal Kombat II > Mortal Kombat, hands down!

MMX2 is better than X???

Huh?

Final Fantasy 2 (4)

I agree with almost everything posted already and it's hard to come up with new examples that haven't been mentioned. What about:

Lolo 2 > Lolo 1
Sim City 2000 > Sim City
Mario Party 2 > Mario Party

Lufia 2 and Breath of Fire 2 are definitely better than the originals.

Pretty much every pc game ever created.

I can't believe no one said Diablo yet.

Diablo 2 is light years ahead of Diablo.

So many great examples in here. Somebody even said TimeSplitters 2 > TS1. This thread is complete.

Warcraft II > Warcraft I by a long shot.

Yes! I missed this one myself, but TS2 is one of my favorite games ever outside of Nintendo. Always played it on Xbox. I liked it so much I went and got the original, and it sucked haha. TS Future Perfect was fun too but I think 2 was the best of the three.

SMB2J > SMB

That is all

The music and scenery is what lured me in. Seemed to have more of a mystic aura about it, IMO bestbplayed loud in a pitch black room at 2am. the other 2 didnt quite hit this sensory gland for me, but they are still fantastic games!

Killer Instinct 2 > Killer Instinct (Arcade)
Toe Jam & Earl: Funkatron > Toe Jam & Earl (Genesis)
Crusin World > Crusin USA (Arcade)
House of the Dead 2 > House of the Dead (Arcade)
Street Fighter II > Street Fighter (Arcade) (I mean my goodness....)
Resident Evil 2 > Resident Evil (PS1)
Wipeout XL > Wipeout (PS1)
Sonic Adventure 2 > Sonic Adventure (DC)
GTA San Andreas > GTA Vice City > GTA 3 (PS2)

etc,etc,etc


To me it doesn't make much sense to use examples that went across different platforms.....quite obviously F-Zero X was worlds better than F-Zero, that should go without saying....

The Legend of Zelda was definitely better than Zelda II. However LTTP was superior to both.

Road Rash II > Road Rash
Earthworm Jim 2 > Earthworm Jim
Virtua Cop 2 > Virtua Cop
Coolboarders 2 > Coolboarders
Syphon Filter 2 > Syphon Filter
Goemon 2 > Goemon (n64)
Perfect Dark > Goldeneye
WWF No Mercy > WWF WrestleMania 2000
House of the Dead 2 > House of the Dead
Half-Life 2 > Half Life
Tony Hawk's Pro Skater 2 > Tony Hawk's Pro Skater
Power Stone 2 > Power Stone
Halo 2 > Halo
SSX Tricky > SSX (Tricky is best in the series in my opinion)
NBA Street Vol 2 > NBA Street (Vol 2 is the best of the entire series by a mile, incredible game, subsequent versions were shit)

Zelda 2's combat system has so much strategy and depth and absolutely obliterates the simplistic combat systems of Zelda 1 and 3.  I love all three games and they are masterpieces.  In fact, it's difficult for me to chose which favorite Zelda game between the first four console releases.  I'm going to cheat and say that my favorite Zelda game is a four-way tie between the first four Zelda console games.  Zelda 1-4

Edit:  That was harsh.  Sorry. 

Lol, Super Mario Kart is garbage.

This may be cheating since the best of the series is on the next gen console, but I'd say Contra. The first was great, Super C wasn't a step backward, but didn't really do anything new except for the overhead levels, so those are about the same, but Contra III is definatly the best in the series imo