Children of Bodom - Hate Crew Deathroll
Childish track names and vocals, but the riffing and effective (over?)use of keys can be pretty sweet.. best track is probably Bodom Beach Terror.
Lordi - The Monsterican Dream
A modern band bringing back 1970s/80s cheese but doing it with a real fresh sound, this is just an enjoyable record.. nothing groundbreaking but its easy harmless metal which makes me smile.
Porcupine Tree - In Absentia
Didnt really like this album on first listen, but after owning it for a week or so I became obsessed. What can I say except really good music.. but I guess everyone here will have heard this already.
Yngwie J. Malmsteen - Rising Force
Before he became a bigheaded guy who rehashes his own music, this guy was close to genious with this release imo, the mix of classical with rock/metal is obvious but theres also random bits of swedish folk ('sounds of the swedish forest' as Mikael has put it once!) here and there, its mostly instrumental which is good for me, maybe not everyone elses cup of tea though. For me this album is his best because its about music and not how many hyper speed arpeggios he can fit into 3 minutes.
Swallow The Sun - Ghosts of Loss
Atmospheric doom metal at its best, some people say their first album is better but personally I prefer this effort. The track Fragile is so good that I've actually yet to get sick of it at all despite playing at at least twice every day!
Incubus - S.C.I.E.N.C.E
Very experimental album.. but I really don't like anything by Incubus after this album. It has an ongoing theme throughout and plays around with so many different music styles it's definately worth looking into I think. Best track here is probably New Skin.. but its kinda mainstreamy.. but still worth a look into if you're after something unusual with a modern feel to it.
System of a Down - Mesmerize/Hypnotize
Yeh so I gather not many people here are fans of this band or if they are they dont seem to like these albums. But for me it's very different from their first 2 outputs (I think thats obvious really) which were decent metal albums but too Nu-metally at times which I can only take in small doses. These 2 albums particularly the latter are very focussed and concentrate on the 'angry and desperate' side of the band's MO.
In Flames - Soundtrack To Your Escape
This is the first album I heard by these guy's and I still prefer it to anything else Ive heard by them (but I am yet to listen to their brand new album so that may change!) This album just has a good feel to it, can't really explain where I coming from here but while listening I just feel like I'm listening to good solid metal - playing it safe maybe but hey thats fine with me sometimes
Added some more:
Black Sabbath - Black Sabbath
Everything about this album is beautiful, not merely because it sounds so raw and awesome.. but because Black Sabbath were pretty much the first guy's to do what they did. It feels inspirational and it's kinda like listening into the history and the idea behind the genre of music I like the most. Most people think their later releases are alot better but this has always been my favourite sabbath album.
Judas Priest - Painkiller
After holding themselves back for so long and having loads of trouble with courtcases etc, it must have been awesome for Priest to come out with such a huge album. So not every track is as great as stuff on their other albums... but this album makes a big statement and imo the title track alone is enough to make anyone buy the whole thing.
And some guy already mentioned it - all credit too him cos I forgot how much I fucking love this album:
Rush - 2112
Awesome concept, awesome music, Tears is SO good lol. Don't need to say much more this album is just amazing.
I also however think that Still Life by Opeth is better than anything above and any album I've ever heard
i'm sure a lot of people will hate my 5 picks, but whatever 
