I recently finished ME2 for the first time, and was pretty underwhelmed. Maybe all the hype I've heard about it jaded me to a degree, but it left me feeling... unsatisfied, which is the simplest way I can put it. It felt like a really, really well done expansion pack rather than a proper sequel.
Obviously not going to get into any specifics here, but back on topic: Yes, TC play play play the first Mass Effect. There's slow parts here and there but it's a game that just... envelops you into its amazing Universe and takes you for an great ride. The last third of the game might be one of the best gaming experiences I've had, actually.
Edit: Also keep in mind that ME1 is more heavily weighted toward the RPG side and less of a TPS (mainly due to the fact that the TPS elements of the game are influenced by your skills and equipment (loot).) Which is why I think many people who've never played it (but played ME2/ME3, the near-complete opposite) get easily frustrated by it and give up. They're confused by the mechanics.
"What the hell?! My bullets are doing nothing, I can't hit the broad side of a barn, and I overheat in a second! This game blows."
People don't usually stick around long enough to see what a powerhouse you can turn into. Shame, really.
Anyway :) Play the game, and stick to it. It's a great experience.
"You can't predict baseball. You just can't." - John Sterling R.I.P., Andy Whitfield. Forever our Champion.
I'm sure it's possible, but do you want to miss out? I played them both and loved them both. I don't nitpick on some of the details like others do, though. I highly recommend playing ME1. It starts VERY slow, but honestly, it picks up and becomes one of the greatest games ever.