Are there any "flawless" long-term franchises?

Are there any "flawless" game franchises that have had about four or more entries in the series? Obviously, the longer a franchise goes on the more likely it is to have a bad outing here or there. I guess in part this is a very subjective question. The only one I could come up with after about a minute of thinking was the Wipeout series. I'm fine with all of the games in the franchise, but I know those weird "hardcore" Wipeout players hate Wipeout Fusion and everything that followed. But for me, Wipeout is a series that hasn't really had a misstep (I haven't played Wipeout 64. I hope that doesn't disqualify.).
 
EDIT: Definition of long term: Poor word choice maybe, but a franchise with more than four games. So, Street Fighter, Need for Speed, Twisted Metal, Wipeout, Metal Gear, Castlevania, et cetera. Not Uncharted, or Mass Effect, or Gears of War. Franchises that transcend console generations, if you will.

I know the other day I was thinking about this and I had a few series that really had no bad games. 
None of which are coming to mind right now. I don't think there really is a "flawless" long-term franchise.
Also define long term!

How long is "long-term?" But truthfully I would say no. No game is ever perfect.

In my opinion, Street Fighter has never gone wrong. (except for Street Fighter the Movie: The Game >_<) 
 
Half-Life has been consistently awesome, but I personally wouldn't call that "long-term".

Mortal Kombat. Flawless victory.
 
Yeah, okay, not even close, but hey, I liked your word choice.

No game is flawless, and none will ever be.

" The only one I could come up with after about a minute of thinking was the Wipeout series. I'm fine with all of the games in the franchise, but I know those weird "hardcore" Wipeout players hate Wipeout Fusion and everything that followed. But for me, Wipeout is a series that hasn't really had a misstep (I haven't played Wipeout 64. I hope that doesn't disqualify.). "

I think all of the Battlefield games have been quality titles. Some may disagree about Battlefield: 2142, but I never understood the perceived hate towards that game.

The only ones I can think of that may qualify as flawless would be Metroid, Zelda, and maybe Half-Life. Nearly every franchise that has been active the past 10 years have at least one bad apple or several.

God Of War for me. Maybe Mario if you just stick with the main games and not mario party and stuff

Probably Metroid. 
 
Metroid 
Metroid 2
Super Metroid
Metroid Fusion
Metroid Zero Mission
Metroid Prime
Metroid Prime 2
Metroid Prime 3
Metroid Prime Hunters
Metroid Prime Pinball
 
That's every Metroid game. Just look at the list. The only two I wouldn't consider to be stunning in every way are Hunters and Pinball, and even they were good.  
 
Bottom line: Every single Metroid game is good.

Monkey Island.
 
Every game has been funny and enjoyable

" Monkey Island.  Every game has been funny and enjoyable "

Well, anyone else here think Age of Empires has stood up pretty well?

Anything from  blizzard

" Anything from  blizzard "

Resident Evil series.

Civilization, maybe? Although that may be a bit of a stretch, seeing as all of the game are, essentially, identical... besides gameplay improvements in between.
Age of Empires is great.
Grand Theft Auto also has, for the most part, solid games.
Nobody knows what I'm talking about with this one... but the Myth games were all great.
Europa Universalis is solid.
Oh, and Myst.

Project Gotham Racing? 4 was badass.

I wish that ten years in the future I could write in a thread like this and say "Borderlands".

Metroid and Zelda, for me. Half-Life maybe...

Infamous.... wait...

Any Bioware game (except maybe Jade empire), in particular id say the Mass Effect games.

Metal Gear Solid series, if you don't include the psp games, more specifically the Acid ones.

Ace Attorney, bitches. Still going strong on that one.

" Any Bioware game (except maybe Jade empire), in particular id say the Mass Effect games. "

I've loved every Halo game so for me personally that's a pretty "flawless" franchise

Mario.  There are so very poor games in that franchise across so many decades and so many systems.

" Metal Gear Solid series, if you don't include the psp games, more specifically the Acid ones. "

I don't think Half-Life can count because there are only two full length games in the series. Age of Empires stumbles on AoEIII. I would have said Forza, but maybe 6-7 years isn't long enough to be considered.
 
I'd say the series that best meet the criteria would be Virtua Fighter, Civilization, SimCity, the Tales series of JRPGs and traditional BioWare RPGs (BG 1+2, NWN, DA:O)

Metal Gear springs to mind for me. I would like to say Silent Hill as well because I personally don't think there has been any bad ones but it doesn't fit in the category really because there has been a definate slow decline in the series for a period of time from 2 up until Shattered Memories. Metroid is also a good choice.

I'd say Half-Life as well. It's been around for over 10 years after all.

The Sims celebrates it's 10th anniversary and if we just look at the PC titles, then I'd count it among the best.  Each of the 3 releases and the majority of the expansions involved were great fun.  If there is a problem with the franchise, it's that there has been some EA over saturation with the add-on packs, but since you don't need each and every one, I am willing to over look that.  Sadly, if we count the Sims franchise's advances into the console and portable market, then things look very sad.  I don't know why anyone would want to play this game on anything other than a PC (or Mac), but I guess that's not an option for some.   Sims on PC, good; Sims on anything else, bad.  Not a "flawless" franchise, true but one that has fared better then most over an extended time period. 

" Well, anyone else here think Age of Empires has stood up pretty well? "

" Space Quest "

" @AgentofChaos said:

" Well, anyone else here think Age of Empires has stood up pretty well? "

I personally hated the shit out of AOE3 (the colonial one). Don't know why, just didnt do anything for me.  EDIT: Also, I'm going to go ahead and nominate the Total War series - Despite the fact that maybe one or two were a bit hinky, they are always ambitious, and always leave me wanting more. "

" Ratchet & Clank.  *runs* "

I am incapable of understanding how anyone who likes metal gear solid could not like metal gear solid 3.
 
God damn. It doesn't just confuses me, it confounds me.

The sims

I'd say Metroid and Half-Life.