The best area of Dublin is called the Temple Bar district. It's Dublin's center of Irish tradition, music, and most importantly, drinking. I've never seen a more concentrated area of merriment in my life. It's an old, fairly narrow, cobblestone street, lined exclusively with pubs and restaurants. There's even a Hard Rock cafe. Most of the pubs have live music throughout the day (and night), and since we happened to be in Dublin for "Trad Fest", all of the music was traditional Irish, although we did hear some classic Green Day and Oasis.
On our first night out at Temple Bar, after purchasing our Guinness and ignorantly wondering why the bartender was just letting them sit at the bar while they weren't filled (to be explained later), we tried to inch our way closer to the live music. We were unsuccessful, but found ourselves next to fellow Americans from Cincinnati. They were both in their mid 20s, and it was a treat to run into fellow travelers who spoke an unadulterated form of English. Unsurprisingly, we ended up seeing them at other pubs that night and at other locations over the next couple of days. Very easy to make friends here.
Our first full day in Dublin brought us to the Guinness Storehouse, Ireland's most popular tourist attraction. I initially questioned if it was worth paying 11 euros for a simple tour of a brewery/storehouse, but I very quickly discovered the brilliance of the Guinness franchise.
Believe it or not, we did more than drink Guinness during our stay in Dublin. We went on a historical tour of some of the city's most interesting sites, led by a Trinity College history grad. Our tour covered the Dublin castle (very disappointing), the viking/medieval area ("dece"), Trinity College, the former parliament building which is now a bank (very cool), and the Temple Bar district. The tour guide was very animated, spoke well, and was very knowledgeable about Dublin, but by far the best part of our trip came just hours before our flight back to our new home.
Having basically seen everything Dublin has to offer, we had some time to kill at around 1:30 in the afternoon. So, naturally, we headed over to Temple Bar for what we thought would be our last Guinness of the trip. The bar was packed with jolly Irishmen who clearly had nothing better to do than drink on a Saturday afternoon, but we luckily got a table next to an older (50s, probably) couple. It didn't take too long for Grace to make conversation, and before we knew it, our new friend Phil and his wife were offering to buy us pints. He would not let us refuse his generous offer, and we ended up conversing with this kind couple for three hours before we had to catch a bus to the airport. This experience, while seemingly minimal, is to me what traveling should be about. You can see historical sites and landmarks, and learn about history, but by far the best memories are formed as a result of the people we met.