Round 1: Apple Mail v Sparrow
For many, Apple's default Mail app is the standard for managing desktop email on a Mac. Despite the steady improvements it's received over the years, Mail lacks in one key area: Gmail support. Google's mail service syncs with desktop and mobile clients such as Apple Mail via the standard IMAP protocol, many of Gmail's features go beyond what IMAP was intended to handle.
Enter Sparrow, an app which offers many features beyond Apple Mail. Like Mail, Sparrow handles most standard email services with ease, but leaps ahead with robust support for Gmail features such as labels and priority inbox. The interface can present a minimal, inbox-only window, or expand to a robust, three column view. The app even natively supports Dropbox and CloudApp for sharing large attachments, as well as Facebook integration for contact photos. Sparrow is a solid alternative to Apple's pre-installed Mail app, and is available on the Mac App Store for just $10. If you don't mind ads in your inbox or a brief Sparrow credit in your signature, there's even a free version: Sparrow Lite.
Round 2: iTunes v Spotify
After its debut in 2003, iTunes took only five short years to become the largest music seller in the United States. Today, the store has expanded to sell software, TV shows, movies, books, and audiobooks, and even host free podcasts and college courses. Competitors have largely focused on what they perceive as the store's key flaw - a la carte purchasing. Alternative services have risen and fallen in an attempt to break Apple's dominance, and Spotify looks to be the most promising candidate.
Originally limited to music lovers in Europe, Spotify expanded to the United States in 2011. Spotify's desktop app (available for OS X & Windows) gives listeners access to a massive streaming library, and is built around social features such as collaborative playlists and Facebook integration.
Of course, the free library limits playback time and is supported by ads, but users can upgrade to Spotify Unlimited or Premium plans ($5 or $10/month, respectively). The former simply removes ads and time limits, while the latter enables features like offline listening, increased sound quality, and full mobile apps. Spotify is absolutely worth a try, especially for music lovers hoping to discover new artists.
Round 3: Photoshop v Pixelmator
Photoshop is so dominant in the field of photo manipulation that it's become a verb. Adobe's crown jewel is depended on by photographers, designers, illustrators, and other artists the world over. For students and home users, however, the price has long been prohibitively high. While Adobe offers Photoshop Elements, the app is a far cry from its big brother's strength and flexibility. Thankfully, there's Pixelmator, an inexpensive and incredibly powerful Photoshop alternative for the Mac.
Pixelmator looks and feels a lot like Photoshop at first - there is a document window, surrounded by various tool palettes. The app matches Photoshop feature-for-feature for most uses, and even includes content-aware fill and image healing. Where Pixelmator truly breaks away, in my opinion, is its tiny footprint.
By taking advantage of the Mac's "under the hood" capabilities, Pixelmator manages to be a speedy and lightweight app that gets the most out of your machine, without succumbing to the massive bloat that plagues Adobe's software. Apple selected Pixelmator as its "Mac App of the Year" in 2011, and given the tremendous power and $29 price, it's no wonder why. For an in depth preview of its capabilities, check out the developer's tutorials page.