The one that I got hooked on back then (and still use to this day) is Autostitch. It was offered as a demo freeware years ago, but AFAIK it's still available free and I've reloaded it a few times since.
It is to me the most simple, seamless, and accurate stitching software I've come across, even compared to pay versions. You set the output size desired (expressed as % size - such as 90% of original in height x whatever the length comes to), choose all the photos to be stitched (you don't even have to pick them in order), and click OK. That's it - it goes to work, and when done, spits out a blended, stitched photo, usually even matching the sky tones if different and working to best fade unmatched objects out. As long as you give each shot a small amount of overlap, the stitch software should be able to grab it and stitch it.
For example, here's a stitched shot what wasn't even taken intentionally as a pano...I had just taken 2 or 3 shots from the train station balcony, and realized when playing around that there was some common overlap. The metering was totally different, skies different, etc. Yet when I loaded the shots into Autostitch, it was able to come up with a match and give me a 'wide' shot when I didn't have a wide camera:
I still use the software with my DSLR shots for any panos.