My personal rating system is quite simple

Games I've tried and did not enjoy
Games I enjoyed playing
Timeless games (or games that made a lasting impression on me and that I'll replay one day)

10) Game changer: Games that have changed the way video games are played.

9) Unparalled amounts of fun: Games that live up to and exceed the oldest standard in gaming-fun.

8) Technical  masterpieces: Games that have broken some kind of technical limitation at its time, while at the same time being fun to play.

7) Excellent experiences: Games that may not have done anything particular to advance gaming, but are still crafted to excellence in most aspects.

6) Great games worth buying: Games that are for the most part well made and fun to play, but have a few minor flaws that hold them back from achieving greatness.

5) Mediocre: Games that are, as the score suggests, at the middle of the pack. Not terrible but not excellent either, worth a look at least to decide if its an experience worth buying for oneself.

4) Flawed: Games that can be fun but have some major flaws that hinder the experience.

3) Not good enough: Games that simply just don't deliver enough fun, developers need to try much harder next time.

2) Terrible abomination: Games that are just horrendously bad with only a few things that are good about them.

1) Migrane inducer: Games that are the opposite of fun and causes pain to the player.

0) This should not exist: Games that should not be called games. They shame gaming.

It really depends.. Sonic 3 & Knuckles will get a 7 from me if I'm not in the mood to play a sonic game... It all depends on what I'm after during the time I rate the game, and, how much time I've spent with it.

10, I really don't know anymore...
9. I... still don't know...
8. This is where most of my games fall, great, but, never getting quite there... If there is something better, once I've seen it, or experienced it, it falls right back here.. No matter how perfect it is, it will still fall. But, I love Marvel Vs. Capcom 2.
7. these games had problems that kept me from enjoying them as much as I could. Megaman X6 is an example. Once, I'd even saved all the hostage, but, it was painful as hell to do.. And, some of them involved you suiciding just to save them.
6. Lots of problems in the game... Tekken 6.. Perfect example. So many features lacking... And, rage mode.. .I love fighters, though I hate fighters that punish you for winning, and reward you for getting kicked around...
5-2 Here's were it gets fuzzy.. Whatever game is right here... who cares? It's crap, either way you look at it.
1. Batman Forever; Sega Genesis... Terrible.
0. This would have to be some game, with terrible graphics, still movement, and no clear objective...

I don't think it's boring. You don't need an elaborate grading scale for your own review. Though, it's different if you are IGN/GI. You need something like a 10 Point Scale.

10-My favourite game of all time. ONE game, because it's the absolute top score and it can't go to many games. In this case MGS3

9- Masterpiece, very few games per gen (U2, Yakuza 4)

8- Absolutely a great game, extremely enjoyable (U3, MGS4)

7- Very good game, very fun experience (GTA IV, AC:B)

6- Good game, satisfying. (InFamous, LA Noire)

5 - Decent game, playable but that's about it (Catherine, BttF: the game)

4- Not a very fun game, I can play without getting much joy from it (DA:O)

3- Bad game, getting it was a mistake (Tomb Raider, the Angel of Darkness, Broken Sword 3)

2- Beyond terrible, the suffering is unbearable (Dark Angel)

1- Horrible abomination of mankind, legendarily bad (Superman 64, ET)

No, that's the opposite of what is needed.

One person can grade or rate on any scale they want to, a simple 2 or 3 point scale is generally indicating the person is not interested in thinking about it, as long as they can recognise the games they like and those they don't. Other people can go into as much detail as they want to grade their own games because they are only in comparison to other games in that person's collection, so it's actually possible to be "accurate" about which games fit where.

If all reviews were always done by the same person (per publication) then huge 10 point or 100 point scales are perfectly reasonable, and aggregate systems like GameRankings and Metacritic actually make sense. Unfortunately that is not possible, big sites like IGN are naturally going to have multiple reviewers that get swapped and changed.... as such any 100 point score system is meaningless at comparing any one game to another. If the system is simplified then it can negate a lot of the bias of opinion between two people, and then if all review scores were similarly simplified aggregate systems can create mean averages that mean something. (Ideally I would say a score system works best with 3-5 options, 7 is pushing it, and an 10 point scale is too much unless all reviews matched that)

Also at least half of any point scale system should be for the good games, though I think most people already agree there has been too much score inflation.

There used to be a video game magazine that had a panel of reviewers.  Each reviewer had a small listing of games they liked (one liked RPGs, another liked adventure games, etc).  They would all rate each game and, though they would come out with different scores, you could look at the reviewer whose taste most closely matched yours to see if it was a game you might enjoy.  I always thought that system was very cool because you could get that "someone like me" perspective which you don't see much of in today's reviews unless you stumble on that one reviewer who just happens to have tastes just like yours.

That does sound like a great system... I would guess most would not consider it "cost effective" enough though, it's cheaper to have each reviewer on a different game.

I guess Famitsu does have something a little like that with 4 reviewers contributing to the total score... How many different reviewers were involved in the magazine you are talking about?