Can we put adsense, bidvertiser, infolinks and other affiliate ads in one site?

Yes you can, but if your blog or site is plastered with ads, and has very little content, it will not rank well with Google. Just a few well placed ads along the side or below the header is much better. Remember, first we add content, then ads.

Google Adsense says you should not place Ads from other affiliate programs. However You can place ads of bidvertiser, adbrite and other ads in one blog or site. I have 4 affiliate ads in my blog and I got paid. no issues.

I am trying few other programs also to check which one is best and high paying.

You can do that, but I recommend 2 ad places at most per blog. Any more then that will increase your site bounce rate meaning that people will live your site as soon as they come. Yes most people make blogs just for the soul purpose of making money, but the key is not to make it look to much like that is the only reason. Also I would like to warn you that in order to use another ad service with adsense such as bidvertiser, adbrite, etc. you must make them look different from your adsense ads, as says google. Also another word of advise would be that if you ever have the option to add Full page ads do not add them because they super annoy people a lot.

The advise I give you is the advise that I have gathered throughout my experances as being a "webmaster."

Also if you so wish feel free to check out my blog for the link is on my profile.

the terms and conditions of adsense and bidvertiser clearly state that you cannot include any other form of advertisements on pages where their ads are included. so it is better to play safe and use different pages for different ads. however infolinks does not have any such condition. so you can use infolinks ads with both adsense and bidvertiser.
also since you have got conflicting views here, it makes sense to read the terms and conditions of all sites you mentioned carefully to get the clear picture...good luck.