Hello friend, I am going to buy 100 domain. I have adsense account. so which web host is best for me.
What kind of traffic are you expecting with these 100 domains? This will be a factor as to what type of web hosting you will need (shared, vps, dedicated).
100 domains? DreamHost definitely. cPanel kind of sucks when you have more than one site, but DreamHost's panel scales so much better.
If you are just looking for a place to buy the domains from, can't go wrong with GoDaddy (about all they are good for IMO) If you want to host your sites, Site5 is a great place to start, 9.95 domains and a non-reseller panel that allows you to create multiple panel logins for your domains (look at MultiAdmin)
Just go for Seohosting.com. It's a Hostgator's company. Hostgator is a name for reliability and trust. You will get all dedicated unique ip's for for each of your domains.