Possible Aliens?

A lot of claims of Extraterrestial encounters/abductions seem to mainly involve these types of aliens:

Reptillians,
Greys
Nordics
little green men
Humanoids of other descriptions.

In fact some even go into great detail descriptions including naming the races and even saying what star system they are from. I have been reading some sites which claim that some of the visits are even motivated by extraterestial politics ranging from enslavement of the human race to preparing us for the galatic federation!

All seems a bit too humanlike/sci fi to me why no Colonial Organisms, Swimmers/Waterbreathers, Gas Bags, Energy Beings, Inscets or even metallic/robotic life?
Why do they (claiments aliens) have similar political/motivational desires as the human race and appear to think quite like us?
Why are Aliens Humaniod, is there a good scientific reason for this or is it just anthropism?

My take is that a possible extrateresstial would look, think, behave in very different ways to us and we would probably not be able to understand them or their intentions properly at all. I can't really see any contact happenning that wouldn't be dangerous or fatal to one of us especially if the alien race was as dependant on resources as us. I also imagine that any significantly advanced civilisation would probably not need a biological form and would be uninterested in us unless we effected it in some way.

Please try and be scientific about this and respect the fact other people may have completely different views, the purpose of the thread is to encourage debate not crititism!

What do other people think about this subject?

[edit on 4-12-2008 by oinkment]

I've heard so much on what other alien species look like/are I really can't say I know what to believe at this point. I've heard everything from 3 maybe four species existing; pplus-45 orions and pplus-52 jrods, us and some higher dimensional being (Dan Burisch's interviews on project camelot), to 57 different types (according to Sgt. Clifford Stone in the disclosure project).

The Galactic Federation of Light stuff doesn't seem very probably, and the only thing about it that makes it interesting is the hijacked radio signal in the '70s (UK). Most of the GFoL is newage type stuff spouted out by "psychic channelers" who I personally believe are masking themselves with a "play" identity to give their words some sense of authority.

I think it is possible that the greys may be real, they are the most reported in the abduction phenomena.

Little green men seems to be a media catch phrase.

I find it funny that people say this and that about how they look but have never actually given any proof other then an opinion or heresay.

I agree, all that has ever really surfaced are some fake photos and sketches. Nothing definitive. When It comes to this kind of thing you can't just "take someone's word for it".