I think I've used almost every kind. I keep one on a drip line to my birdbaths year round, just removing them when the temps go below freezing so I can turn the faucet off. I have had good luck with the Melnor, which is what I've had most recently. The one i have now has lasted well and I have not had to replace the batteries for over a year, even tho' it turns on 4 times a day, every day. The trick I finally learned, after blowing through batteries, is I now have a plastic tub/bucket placed upside down over the timer (it's large enough to fit over the faucet handle and timer) to protect it from the rain. It's made such a difference in the longevity of the batteries.

It's easy to set and easy to override if you want to do something manually. I have the kind that also has an outlet that isn't controlled by the timer so I can put a hose on it and use it without disturbing the timer:

my timer

What model of melnor do you have now?

I linked (in green where it says "my timer") at the bottom of my post. Those links are sometimes hard to notice, I know.

Oops. Thanks.
I called melnor a couple three weeks ago to ask about their products. Awesome customer service. They spoke to me at length, and were very helpful.

I think the moisture (rain) in the nw shortens the life of the digital timers (ironic, huh?) and definitely causes battery use to increase. I'd tried covering it with a zip lock bag, etc. but the bucket has been the answer to keeping the battery usage low and I suspect the life of timer will increase. I'm very happy with this particular one.