Dark Lunacy incorporates lots of strings in their songs. They're sort of thrashy/death, but you might like 'em nonetheless.
He's right...they incorporate lots of strings in their songs; just not very well, at least on their first album. I haven't heard the last album so I can't judge, but as far as arrangements go, the first album was basically four metalheads wanting to put strings with death metal and not knowing anything about arrangements or structure. I've seen them live and there are no strings live; it's all DAT. Basically, they put a violinist in the studio to play a part, and they stick that part in with another death metal part that doesn't even belong with it.
What I can be sure of is Therion, namely the albums Theli, Vovin, and Deggial. I've seen them live and they are 100% real. Of course the orchestrations are DAT live, but the entire choir is there live.
Someone mentioned Ram Zet. Great, great blackened/gothic/industrial/orchestral band. Structures are fairly simple but done well, nonetheless.
Haggard was also mentioned, and I have also seen them live and they are also 100% real. Great band, great musicians, great structures, great arrangements. It's actually more classical than metal, but there are some pretty heavy parts in there. I think you'll really like it.
If you're looking for something with just a violin in it, look no further than My Dying Bride's albums, "Like Gods of the Sun" and "The Angel and The Dark River". They are very melodic and very musical...and some of my favorite albums. I've seen them live (finally) and they too are a great band live.
Stay away from that Metallica S&M abortion. I'm not even speaking about Metallica, either...the orchestra was arranged so horribly I can't even listen to it. It's classical music in it's most base form, which is why I guess it fit with Metallica.