I always sleep my Mac Mini, only rebooting when a system update requires it.
I love the convenience of it being ready to go as soon as I need it. I can stop what I'm doing and sleep it, then go straight back to where I was when I get back.
Plus, I find the soft pulsing sleep indicator strangely reassuring
The other cool thing is that my bluetooth phone stays linked to the Mac even when it's asleep. When my alarm on my phone wakes me up in the morning, the Mac wakes too. I can stumble over to the desk and glance at a few emails before wandering into the shower.
Experiment with the scheduling options in Energy Saver o get a setup that suits you. For example, I wake up at 6:30am and the phone's alarm wakes the Mac too. It's scheduled to go to sleep when I leave the house at 7:30. Then, it's scheduled to wake at 7pm when I get home. It'll then pair with my phone again when I get within range, and sync my address book, calendar and task lists with the phone. If I don't use it, it'll go to sleep again 15 minutes later. But it'll stay paired so that if I receive a call or SMS message, the Mac will wake and log the call/message.
Overall, I just find it very convenient to have a computer that's available when needed, and which has the smarts to wake when it's got something to do, and sleep when it hasn't!