what is the sound difference between the altec lansing iim616 and UE metro fi 200.
I am getting both at the same price. Which one should i go for?
I would like good isolation, depth in sound, decent soundstage

im616, check, check, tie
metrofi, nope, nope, tie

im616 wins

i was also wondering if i should up my budget a little and get the grado sr60. ive read reviews saying they are amazing. are the grados much better than the altecs and UE? should i go for them

the grado's are totally different animals though, being open headphones. They won't isolate at all. So the question is how much do you value isolation and what are you using your cans for?

However iems and headphones sound different and generally a cheap headphone (ie. sr60) will beat iems at the same and higher price. Though I haven't heard the grados, they should provide a larger soundstage. Ultimately it depends on what your using the cans for.

yea i know the grados are a totally different sound when compared to the iems.
thing is i am using a creyin canal earphones and somehow i have never experienced the headphones. if i buy the altecs it will be much better than cresyns but still will be iem. grados will be different.
So just wanted to know is it worth spending more for the grados or sticking to altecs is also good.

If by cresyn canalphones you mean the Creative ep630 or similar, then you are looking at headphones with an opposite sound signature. The ep630's are bass boomy and dull. The im616 are very like an Etymotic er6, analytical and bass light. The Grados are also bass light and lean towards bright. The Grados are one of the worst full size headphones for size of soundstage and the im616's also aren't great. That being said, I liked the er6 and love my Grados.
A lot depends on the type of music you listen to, your preferences (detail, bass impact, etc.) and where you will be using the phones. The er6/im616 are very detailed and provide terrific isolation. They are iem's and you will have to insert them deeper in your ear than you would your cresyn's. I just could not get used to the lack of bass. The Grados are a fun headphone to listen to, especially good for guitar rock. They don't isolate from outside sound at all and anyone in your vicinity will also be listening to your music. A lot of people find them uncomfortable to listen to for long periods of time (fit). I got used to them and they don't bother me.
Both headphones are very popular and if you do buy them and don't like them, you could sell them without losing too much.

Choosing between Altecs and Metro.fi depends on what music you like. If you like vocal, classic, jazz, or something not "dynamic" then Altecs are great. If you like power and impact, forget'em.

I own Altecs IM616 and Denons C700. The Altecs are great when I want to listen Katie Melua, Andrea Bocelli, Louis Armstrong ...etc. Vocals are outstanding. But when it comes to some 'harder' music with impact, i.e. Dream Theater, Pagan's Mind, Therion, etc. Altec are tiny and flat. For this kind of music, Denons C700 are just great.

So... if you like deep sound and soundstage, you should consider Denons C551 - they're in similiar price range as UE and Altecs.