Recently, i've acquired copies of both Mass Effect games for PC (with all the DLC's for both), even though I've already got both games for the 360. 

I've must say that i'm falling in love with this series all over again. I've finished a full Renegade run on ME1 and exported it to ME2 for a full renegade run as well (ME1 was completed on Veteran, doing ME2 on Insanity). 

First thing I noticed, both games control much, much, much better than on the 360. The extra amount of buttons really gives an extra omph to the strategic input of both games, while making the task of completing them on higher difficulties a much easier job (haven't died once on Insanity on ME2 and have completed Kasumi's Loyalty mission, which is one of the hardest in the game). 
Also, graphical fidelity is much higher on the PC. Of course, ME games are already graphical powerhouses (I'm always stunned on how beautiful the first game still is), but with extra enhancements on the PC's, they become much better. 4x AA and 16x AF really do wonders for ME2 (it's pretty well optimized for PC, I must add), while the Extra quality textures for ME really puts it's on par with ME2.

Sadly, I noticed much more bugs and glitches on ME1 PC than on the 360. Square texture tiles on uncharted worlds, lots and lots of pop-ups, and a very screwy FPS, even when turning down the AA and AF to 0 and 4 respectively. Heck I was getting as low as 20 FPS sometimes, and ME2 is a constant 60 on any situation. Pretty shoddy optimization job they did with ME1.

I'm really dying to play ME3 next year. I've got some various playthroughs so I can experience pretty much every outcome (I just need to do a full Paragorn run, as my playthrough on the 360 is based on personal choices, rather than paragorn or renegade runs. That, and I went for both Paragorn and Renegade achievements at the same time on ME1).

Has anyone tried this awesome series on the PC as well?

I have them both for 360 and PC too and to be fair ME1 is simply better on 360 in my opinion... whilst there are no game breaking bugs or glitches on ME1 for PC it just feels more 'clunky' than on 360,although I have noticed that ME2 is far more smooth and slick on PC and as such much easier than on 360. ME2 on the PC also obviously has improved graphics such as better textures, higher resolution and so on plus it runs faster and smoother but I find the scan system and going through the menus almost infuriating sometimes because I occasionally forget that it isn't a one click system like the 360's version. One thing the does favoure the 360 version over the PC version is that I can play it on my super TV.

Mass Effect 2 on PC is just a joy to play. ME1 wasn't very well optimised as you say, but still a lot of fun. Obviously, looks wise, on PC they're both stunning.

I've played ME1 on both PC and 360 (though only completed it on PC) and played ME2 on PC only, but IMO the difference between PC and 360 in case of Mass Effect 1 was negligible. At least I didn't have any problems with the different control scheme and I didn't find more bugs in one version.

Fortunately, my laptop has an HDMI port, so I'm able to hook it up to my 19" LED TV (can't afford any bigger), that's how I made  the  graphical comparison between the 360 and PC versions.

But I agree with you, ME1 on the 360 is far smoother and  less clunky than on the PC, mainly because it's badly optimized for it.

One thing I had troubling me with ME2 PC were the long loading times, which I found it was a multi-core compatibility issue. Nothing that a fine tuning of the affinity on the taskbar couldn't handle.

Didn't you notice some texture problems on the surface of the explorable planets? Like instead of being seemless ground textures, you could notice square tiles of texture?

On the PC version I had that on every planet I explored with the Mako, while on the 360 it almost never happened. 

No. I'm pretty sure I would still remember it if something like that happened (especially frequently).

I'm gonna ask a stupid question and it's probably not an issue, but are your drivers up to date? It could just be that. I haven't played the original for a while but I can't remember any major texture problems.

Yeah, I always update to the latest drivers and I haven't had any kind of texture issues in any game before. I'm using an NVIDIA 9800M GTX.

Ive made the switch myself, im definitely gettin me3 on pc.