Context: I've played every Bioware CRPG game to completion, multiple times. I love the company, and I love their games. I only play PC CRPGs; I don't own a console.
Dragon Age: A traditional "western" CRPG in the mold of Baldur's Gate. Elves, Dwarves, Dragons, etc. A large world to explore. Complex skill/magic trees and extensive inventory management. Many quests and NPCs. Rich storyline. I'd say it's definitely worth playing, but I also admit that it has some weaknesses.
- Highlights: interesting and memorable companion characters, lots of gameplay, good tactical combat (very 4e - PCs have clear striker/defender/controller roles, monsters are explicitly divided into minions/regulars/elites/solos), some interesting moral choices especially near the end of the game, epic scope of quest.
- Lowlights: core enemies are cliche (big bad enemy with hordes of "orcs"), extensive copying from other sources (several scenes are almost shot-for-shot copies of the cinema-version Lord of the Rings, and other elements will seem very familiar if you've played the earlier, and more "adult", CRPG The Witcher).
Dragon Age 2: A "simplified" version of Dragon Age. Less inventory management, fewer skill choices, more linear maps, simpler combat (with "splashier" moves - enemies explode into clouds of blood, even from simple sword strikes). If you prefer console RPGs, this will seem more familiar... faster paced, easier, and quicker to complete.
- Highlights: In my opinion... very few. There are a couple of companion characters who are interesting, and there have been maybe 3-4 quests (out of many dozens) which really surprised and/or impressed me.
- Lowlights: In my opinion... nearly everything else. This is the only "bad" CRPG Bioware have made, in my opinion. In addition to the extreme simplification, the game is simply lazy. For the first time in a Bioware game, nearly every map is extensively re-used. For example, there is a "rich house" map. Every time you go into a manor, palace, or upper-class home... it will use the "rich house" map. Same is true of caves, ruins, slum house, back alleys, etc. There are, perhaps, 12-15 different interior maps in the whole game. And you will revisit those maps a dozen times each. The monsters, traps and treasures may be different, but that's it. Even the main setting remains the same: in the first part of the game, you're in a city. In the other two parts, you're still in the same city (with the same maps)... but simply 3 and 6 years later, respectively. It's extremely repetitious and, frankly, somewhat embarrassing coming from a company renowned for creating memorable settings. Further, the primary setting (where you'll spend 80% of your game-time; dozens of hours) is a generic fantasy city. There is nothing exotic about it or its inhabitants in the least. The storyline is also extremely generic - there are no truly compelling protagonists (unlike Baldur's Gate or Jade Empire or Mass Effect) and no interesting character motivations (unlike Planescape Torment or Mass Effect 2). My advice is to play the first game, and pretend that the second doesn't exist. Much like watching The Matrix movie.
Dragon Age RPG: I've had limited exposure to it (played demo copy once). It feels like a generic "entry-level" RPG to me, although the rules seemed poorly structured in the rulebook (difficult to find certain things - could have done with better editing). Little guidance to encounter design, so perhaps not a great game for the DM. PCs seemed okay, but it didn't grab my attention. Without the setting fluff (which isn't exactly novel, in the first place), I'd say that 4e, Pathfinder and Warhammer FRPG are all richer choices.