Help: AM antenna and AM reception


Hello all: I would like some suggestions and advice on AM reception. I know this may not be a popular format but a couple of the stations I enjoy broadcast in AM only.
My experience with AM reception using the "mainstream" FM/AM tuners has been very dissapointing (said tuners being JVC FX1010, SONY SA5ES and Denon TU-800). I tehn bought the Denon TU-680NAB (supposedly optimized for AM performance) but still no luck. OTOH, a pre-wired whole house intercom system with am/fm radio does a FAR better job with the AM stations! This creates a problem with my spouse who says that I spend so much on tuners which are unable to compete with much cheaper syatems! So, what gives? Why does a $300-$600 tuner fail miserably while an "el cheapo" combo am/fm/intercom does so much better? I should say that the antenna used for separate tuners has been the Terk AM indoor type. How do I improve upon this? My location is central NJ. Thanks.
PS: Do let me know if I need to provide additional info.
upgrade1394
Thanks for all the responses. I do agree that older AM tuners had good performance BUT I want to stick with tuners from late 1980's to current. One of the posts also confirmed that Car head units have better AM performance- I totally AGREE! This is another sore point, I can get the same station MUCH better in my car with its cheap $150 head unit BUT my dedicated JVC/SONY/DENON [FX1010, S707ES, TU-800] are lousy at getting the same station. I have even tried taking the tuner outside (OR putting the Terk antenna outside window) but still no improvement. BTW, [Ryammh1]: I have also owned Sony S730ES 2 times and it was not very good with AM reception - too much static and a continuous droning noise in background.
For those of you recommending Grundig/Sangean models: I have tried that route also. Currently have a Sony SW-777 (very pricy) and also a Grundig (Model 2000?) but both have same problem. And yet the cheap $100 unit which builder installed as part of whole house intercom system continues to beat all these pricy units! As the weather improves I will install a "long wire" antenna and see if it makes a improvement. Regards to all those who posted.
I've found that the GE Superadio II portable is superb on picking up am signals. It also has a good sound with adjustable bass and treble. They usually go for $75-100 on Ebay.
I use the CCrane Twin Coil Ferrite AM antenna to pick up my favorite sports talk.. http://www.ccrane.com/am-antenna.aspx Much better than the Terk AM/FM I used to have.

I've measured about 40 db SNR on a distant station using that and their Select-a-tenna in tandem.