Here are my unsolicited opinions on my favorite baby items:
The links are examples, not necessarily the exact item I used. 

Best/Most Used Items:

• Travel System (stroller and infant carseat/carrier combo)

• Boppy (great for helping to feed/hold baby… later for propping baby in semi-upright or belly position… liked having the removable/washable cover)

• Swing (we borrowed my niece’s travel swing… great for moving from room to room, though the full size ones are awesome, too… this is a must have IMO)

• Binkies/Pacifiers: We used both Maam and Nuk brand and liked them both with our first; Baby Girl likes the pink Mams

• Bottles: We used Avent and Playtex drop-ins and like them both for different reasons… Avent traveled better, but Playtex you could squish out the air: I’ve also heard good things about Dr. Brown and the Playtex Ventaire kinds… This may be trial and error so don’t buy too many until you know what Baby likes.  Note: they don’t drink too large of quantities at the beginning so I’d start with the smaller sizes to begin with.

• Diapers: We have stuck with Pampers for the most part… started with their Swaddlers and moved to Cruisers… Diapers are best bought at a Sam’s club or similar bulk store.  You will use a lot of diapers.

• Diaper Cream: I guess we’re a Desitin family.  Good stuff.  I have found the creamy version has a little less of the Desitin smell, but it doesn’t stick quite as well.  You’ll go through a lot of this, too.

• Diaper Bags: I think it’s good to have a couple and of varying sizes depending on the length of your outing. 

• Wipes: We have used Huggies because they sell their refills at Sam’s club.  Pampers has some that smell really nice and are softer (Baby girl gets these)

• Bouncy Seat: this was great.  Seat vibrates and keeps them entertained.  Lightweight and portable, too.

• Changing Table: we debated this for a long time, but we have decided that it was worth it.  Now we change the kids just about anywhere, but a changing table puts the baby at a good height for taking care of them.  I also really like the terry cloth covers that go over the plastic cushion. 

• High Chair: You don’t need it right away, but we have really liked ours.  They have wheels on them now so you can put the kid wherever you want them; they also have dishwasher safe trays.  Avoid any cloth on the seat because it can be hard to clean.  Lot lots of good models out there.
  

• Saucer: This is good when the baby can crawl and working on standing.  It is very entertaining, but they have some independence.

• Pack n’ Play: We use it more on baby #2 - good for keeping one kid in place and the other out of it.  They also can be a second crib.

• Glider: We still use ours to read to our son or to rock him to sleep.

• Things for catching spitup, pee pee and misc. other stuff:   You can use cloth diapers, bibs, pads, etc., but you will use them a lot

• Mobile: we liked our mobile… part of it that acts as music box is still on his crib.

• Monitor: Good to know what noises baby makes.

• Thermometer: we started with an ear one, but a friend recommended this one that you rub over their foreheads and we really like it (we use it for ourselves too).  It doesn’t require any of the probe covers.

Safety:

• Fireplace protection: My husband has a scar from a hitting his nose on the fireplace hearth when he was a toddler so we purchased this.

• Cabinet Locks: they are annoying as anything, but they do keep the little booger out of our cabinets.

Other things to keep on hand:

• Baby Tylenol, Baby Shampoo/Soap, Baby Lotion, (they don’t recommend using baby powder like they used to because they say baby can breathe in the dust), nail clippers

• Could have used more socks (people bought cute clothes for us, but few came with socks)  Favorite socks: Old Navy

Middle of the Road items:

• Baby bath: probably worth it, but they outgrow them fairly quickly.

Things we didn’t use or didn’t use as much as we thought:

• 0-3 month clothes… they grow fast that first year.
  

• Front carrier… bought one used, but didn’t find the opportunity to use it much (This changed a little with #2… using it more now)
  

• Diaper Genie: this is a tough one… when we were in our ranch house, we used it all the time… we changed the baby in the same place so the diapers were always in the same place.  Now, we change him anywhere as mentioned before so we don’t use it at all.
  

• Receiving blankets: you need some, but we had too many
  

• Baby comforter set: we use it now, but for over a year, the comforter was wall décor  (these sets can get pricey, but they can also make for one darn cute nursery!)  Bumper pads are included in these sets… there are different opinions on whether they should be in the crib with baby or not.  We went back and forth on the issue.
  

• Baby Bath Towels: adult size ones work just fine