I'm a long time Gmail user (I got my invite many moons ago by spelling a girl's name in pepperoni slices on a pizza, from that gmailswap website!) -- and I've been impressed with its evolution over the years. The ads are negligible, since they're all text. The interface is smooth and simple. You can store almost limitless messages, and as promised in the beginning, the storage space increases by the minute. I can't find much not to love about it.
Last year, I got MobileMe. I'd had .Mac before and wasn't thrilled with it, so I didn't keep that long - but MobileMe is like a whole new animal and I really love it. I have my iPad, iPhone, iMac, and Macbook Pro all perfectly synced with my email and calendars. I'm still learning how to make use of all the storage space. I love using iWeb for my website (I still use Wordpress to blog, but I link in the RSS feed with iWeb and have my domain linked with that). Honestly, MobileMe is great. I don't really pay $99/year (I ordered my box on eBay last year after my trial expired, and it didn't cost but about $54, or about .15 cents per day) so it is definitely worth the price, to me.
Since I got MobileMe, I generally just have my Gmail forwarded to it. I can't seem to "let go" of Gmail, probably for sentimental reasons, but there is no practical cause for me to prefer it any longer. Google Voice is not something I feel I need, since I have unlimited long distance through my cable company, and lots of minutes on my AT&T wireless plan. I don't really use Google Docs anymore, now that I've got MobileMe iDisk.
I'm starting to really appreciate MobileMe, even though I haven't really dug into all its uses and features yet. Find My iPhone/iPad is valuable to me.