First off, I would suggest NOT changing the battery unless they're actually dead. Get yourself a decent multi meter if you don't already own one. Here are four decent budget meters:
edit: If you don't already own a multi meter, I highly suggest picking one up. This wont be your only use for it. Any retro gamer can make use of one time and time again, and you don't need to be an electronics wiz. You can use it to check fuses, power adapters, and AV cables. Those three examples are easy checks for very common problems that require very little knowledge of electronics, but the list goes on.
Whatever meter you get (or if you already own one) don't use the battery tester setting if it has one. Those are just a simple pass/fail and are kinda useless. Instead, use the DCV setting and touch a probe to each side of the battery. Don't worry about polarity, you wont blow anything up. You'll just get a negative voltage reading if you touch the wrong sides of the battery, which doesn't matter since you can read it either way (this is also how you would figure out the polarity of, say, a power adapter or power input).
All of those coin cell batteries you mentioned are 3v. Use the DCV setting to see how much voltage is left in the battery. Me, personally, anything 3v or more and I leave it. A new battery should have a little over 3v, usually something like 3.3v. Some people will change them even if they're at 3.0v, but I think that's a waste. Nintendo used brand name batteries in all their carts. Even at 3.0v you should still have a lot of shelf life left.
Changing the battery risks damaging the cart, so I would only change them if necessary. Also, it's a waste to dispose of a battery that isn't dead yet. I test all batteries, AA, AAA, etc. You'd be surprised how many good batteries you've probably thrown out over the years. I'll save AA and AAA's when they're slightly below full charge because they're good for TV remotes that don't require a full charge.
Secondly,
don't use the tape method. Ever. There's plenty of viable methods for replacing the batteries in carts. The tape method is not one of them. It should never have been posted on the internet. It is FAR from being secure, any small bump to the cart could cause the battery to lose connection at any time, and even a split second of power loss could mean lost saves.
If you really can't find any tabbed batteries, then another option would be to install a battery holder. You just have to make sure you get one small enough to fit inside the cart. But brand name tabbed batteries exist, so I would just get those.
Panasonic CR1616, $1.43/ea:
http://www.digikey.com/product-detail/e ... -ND/301860DigiKey doesn't have any CR2025's with tabs, but Mouser does. I'm not sure what style tab you need for GB/C carts, so I'll just post a link to the search results:
http://www.mouser.com/Search/Refine.aspx?Keyword=cr2025You can also get a holder/retainer for the coin cell batteries, that way you don't have to bother with the pre-tabbed ones. It makes changing the batteries down the road easier as well, but if you're looking to replace with brand names then this shouldn't be a concern.
http://www.digikey.com/product-search/e ... 0?k=cr2032CR2025 and CR2032 are 20MM. CR1616 is 16MM.
The other options are kinda bullshit, but still loads better than tape. I'm assuming you already know that you can't solder to the batteries (they'll explode!). One option would be to remove the tabs from the old batteries and weld them onto the new ones. Assuming you don't own a tack welder, you can build one using a disposable camera or other parts. There's plans for this on the net. This can be dangerous if you're not careful. It's also only as reliable as good of a weld you can make from your rag-tag welder. Another option is to remove the tabs from an old battery and use a conductive glue to fix them onto a new battery. This is an OK solution, but you're still at the mercy of the glue bonding. In both cases above, you can use a small bit of wire instead of the old tabs (removing them is a pain in the ass). But both cases, why bother with something that just isn't as good when tabbed batteries and holders exist?
I'm glad you're looking to get name brands and not China batteries. Those no-name Chinese batteries just aren't worth it. But also be weary about where you buy your brand name batteries from. You might find bulk Duracell or something on eBay for an amazing price, but you don't know how old they are. They could be new old stock, and you don't want old batteries. I've bought batteries before that were dead in the factory packaging. If you're gonna buy off eBay or Amazon or something, ask the seller what the expiration date is. Also, I'm sure counterfeit batteries exists from China, just like just about everything else in the world. Places like Digikey are the best places to buy them from. They're much cheaper than retail, which is gonna be something like 5x the price or more. And you get price breaks starting at 10 pieces. And you can be sure they're not counterfeits or past the expiration date.