Almost all kalyani!
Unless it's Balamurali singing it, but even then, it's not as good sometimes unless it's Ninnuvina or Gathi Neeve or Sangeethame or ahhhhhh Sogasu Nee Sommu (I don't think I can ever have enough of that one). And of course there's also the ashtapadi Sakhi He, tuned in Kalyani by Balamurali - that was the first time I heard how exceptionally good Kalyani could be. Ninnuvina is also excellent Kalyani, and in a different mood (more fast paced and energetic than lingering and romantic). Thyagaraja's Sundari Nee is somewhat similar to this, I think.
Oh and kambhoji. I disliked it the first time I heard it (Sri Raghuvara, Thyagaraja), and grew to like it a little after much repeated listening. But Evarimata (Thyagaraja) and Simharoopa (Purandaradasa, if I remember right) are a bit better. Still, somewhat boring. However, I have heard good movie songs in kambhoji -
Premodaaranaay (Movie - Kamaladalam, singer - Yesudas, music director - Ravindran), and
Samaja Sancharini (Movie - Parinayam, singer - Yesudas, music director - Ravi).
I'm not as sure but I think this goes for begada too. There's this movie song that I love,
Innale Neeyoru (Movie - Sthree, singer - Yesudas, music director - Dakshinamoorthy). But I haven't liked any of the carnatic pieces I've heard in begada - not yet at least - but then I haven't listened to a lot.
Mohanam - Another overrated raga! I'm sick of hearing it everywhere. There are few really really good pieces in this raga, the rest are all the same old boring, sickeningly sweet drawl. It's hard to render this raga without making it boring. Less use of the panchama makes it a bit more attractive - this works in kalyani too, incidentally.
Hamsadhwani, sometimes. Although as in the case of mohanam, this is also the fault of those who use it uninnovatively. Sadashiva Brahmendra's Gayathi Vanamali is a notable exception (partly because of the madhyama shruti too - though it would be almost as good without it as well). All his compositions do present a different usage of ragas from their usual.