Well I can't say I'm very informed on trucks and SUVs but on cars it's certainly a mixed bag. Assuming you mean American owned car companies(which aren't exactly American made) and If we're talking about reliability then US cars have certainly improved. Fords are getting much better than they were 10 years ago and Chevys affordable small cars are coming along but still have a long way to go. German cars haven't really been keeping up in terms of reliability. There's a lot of variety among the major Japanese brands.
I think the country that's really started to shine on the small car front has been S. Korea. Kias were once some of the junkiest things you could get here, but they've come a long way. Hyundai is arguably turning out the best small cars now and has recently had the highest owner loyalty as a result.