Both games are good in their own ways in my opinion but I haven't played RIFT much.
RIFT is free to play indeed so you can always just download it and try it. You'd have to buy Guild Wars 2, but it's a one time purchase that's it. I agree with Redshirt 24 in that RIFT is the more traditional MMO of the two. There's indeed no holy trinity system in Guild Wars 2 (no actual 'tank'/'healer'/'dps-focused' classes, you can be a bit of everything in between with all the game's classes depending on your builds).
Also GW2 is very much solo-friendly although of course you won't experience everything there is to play if playing mostly on your own, but playing alone can lead you to end-game content without a hitch. Speaking for myself here... but the lack of holy trinity system was in and of itself a loss of incentive to group up with others to play. Had there been a more traditional approach I'd would have ended up going 'tank' and grouping to help tanking dungeons (as I do in most MMORPGs I play). It's ok though GW2 doesn't 'have to' have a trinity system, it wasn't the devs' intentions it's alright, it's a different approach to MMOs (it's just not for everyone). I'd say that GW2 is still a solid game and there's regular updates.
The production value is good with GW2 as well, I love the soundtrack, the environments' quality, some of the maps have well-crafted layouts, some complex with a bit of secrets to find and platforming thrown in. Additionally, the maps can be quite large, and all of them combined form a gigantic game, in fact I thought that it was rather intimidating to explore, it can be very time-consuming if you intend to discover everything in each of the maps. I really like most of the animations as well (the dancing animations, however... that's another story but it's also my opinion anyway) most of the voice acting isn't bad at all (most is the key word, because there's definitely exceptions here and there, cheesy stuff but not in a 'purposely so' way, more like in a 'voice actor completely missed it' way).
But yeah, at least RIFT is free anyway so just give it a try and see. And despite the fact that I don't play much GW2 I think it's definitely worth its price nonetheless.