what do you reckon was the best thing that google ever did which made them so popular ... adsense, adwords, local search, etc etc..

For me it was SAFE search, all thou there are a small holes in the Safe search algo it did limited the amount of adult spam ( disney -> porn ) and therefore made it a safe place for Families to search

Added :
worst thing : releasing an Algo with only 4 signals

DaveN

I would have to say the perception of more relevant results than the competitors.

At one point, I felt like Sergey and Larry were 'one of us'. They were the little guy against the big unfriendly corporates. I wanted to see them win. I wanted to see a shop built on freebie unix and pc's win against the big guys.

Yes, they had a great product, but if google seemed like 'one of them' or just a bunch of jerks, I might not use them as much as I have.

At one point, I felt like Sergey and Larry were 'one of us'. They were the little guy against the big unfriendly corporates. I wanted to see them win. I wanted to see a shop built on freebie unix and pc's win against the big guys.

Yes, they had a great product, but if google seemed like 'one of them' or just a bunch of jerks, I might not use them as much as I have.
They are still on the side of the little guy... it is just that the big guys are using methods that have to constantly be countered and in the process a number of the little guys get lost in the exchanges.

Sorry, AW, but that is just stupid to me. Google is on one side only and that's its own. Google is a business, and is now a publicly traded stock.

<added>
Or, was that tongue and cheek?

Sorry, AW, but that is just stupid to me. Google is on one side only and that's its own. Google is a business, and is now a publicly traded stock.

<added>
Or, was that tongue and cheek?
I would never deny that Google is a business and with it all that that means. However, it is a search business and the two founders see the organic search side as the tool that got them where they are. If they compromise the intent of the organic side they lose their credibility.... we are not the average user... we are people like the Google business model that use engines as our livelihood... but there is a clear division in the Google approach.

The best thing Google ever did was show the others that a simple design focused on search was better than a sea of ads and other programs.

BEST Thing: A nice clean search box and results not cluttered up with banner advertisments. As well as always giving more strength to the natural (organic) listings, since their algorithmic search is what its all about when reaching relevant results for users. The paid option is was even a better move to give marketers even more real estate space on the first results page.

The WORST: Creating a monster from PageRank, although the monster was fed by the webmasters/site owners themselves. Now it's a fat monster that looks pretty scarry to fix.

The best thing? They were the quickest. Google was the best way before adsense, adwords, local search etc because you could get decent results in a matter of seconds. I first heard of Google long before ADSL hit the streets, and remember, Yahoo/Ask/Rest aren't exactly optimised sites, and it was even worse back then. It was nice to have a search engine that was good, and that was all it did: Search.

After that, Google just gained momentum. Google indexed more and more, more and more people became aware of it, and the rest is history.

So the best thing they ever did? Return an index in under 5kb.

I would say their ability to freely deep crawl the web like no other SE can or does.

Google's greatest assets according to me are,

1.Speed of Information Retrival
2.Simple design
3.Staying as a Vortal with less interest to become a portal
4.Active crawling of the web to provide users most relevant information,
5.Attractive algorithm like Pagerank which made many webmasters glare at the toolbar,
6.Safe searching as DaveN said keeping the porn away from normal searches,
7.Most relevant results than their competitors,
8.Paying more attention to Organic listings than Paid listings, ( Other search engines are more money minded compared to google )

The best thing according to me is the speed,

Not good: These days i am not too happy about google, They are starting to be money minded as against how they were a year ago,