In my 3 years and almost 4 months of being a mother, I have fixed/fed/cleaned a lot of bottles. A lot. Really. We have primarily used the very inexpensive simple Gerber or Evenflo classic bottles; we've never been thrilled with them, but they're cheap. We have one of the BPA-free Avent bottles; the wide mouth is great, but they sometimes leak & soak the baby.
When we accidentally left the diaper bag behind in Florida and didn't discover it until we were a couple of hours down the road, I had to stop at a store to get bottles. I decided to give the Playtex Drop-Ins Premium Nurser a try, since I could just switch out the liner & wash the nipple for the different feedings as we traveled.
I am in love with this system!! We now have two of the nursers and 4 of the rapid-flow nipples (the bottles come packaged w/ slow-flow), and I would rather use them than any of our other bottles. Not only are they simple to clean, but you don't even have to wash the nurser at every feeding. A quick wash of the ring, a new liner, a clean nipple, and you're good to go. The mouth of the liners & bottles is wide, making it easier to mix formula. Also? They do not leak. Ever.
I can't believe I didn't try them sooner! For more recommendations, visit Things I Love Thursday at The Diaper Diaries!