This question has come up before in other threads, and a few recommendations have appeared (I intend to collate some here later) but not all of them mention whether they are easy to grow or how reliable, prolific or early they are (these last two are sometimes the same thing).
Not many websites cover all these important attributes either, and then only occasionally.
The more varieties with personal recommendation the merrier!
If anyone can recommend a mild tasty pubescens or baccatum type then I'd be particularly interested as these have a reputation for easy overwintering.
I would recommend 'Habanero Trinidad' as my absolute favourite for its strong spicy flavour but it is very late - so I've had enormous trouble ripening them in my unheated greenhouse, and even then the seeds inside have been disappointingly puny.
From looking at various chilli sites it seems possible that 'Trinidad Perfume' and 'Tobago Seasoning' are almost identical to HT. I aquired a few seeds of both, but they were puny too, and the plants were if anything weaker and later than HT.
I have no idea what Aji Dulce#2 taste like but mine were just as late.
But that's just my experience and there are so many random factors in gardening...
I am trying overwintering HT this year and if that doesn't work I may try grafting it onto C.pubescens rootstock.
Has anyone else already tried chilli grafting??
Nothing else I've grown has proved quite as spicy as HT but I can recommend two reliable mild, tasty, early and prolific types:
Cherry Bomb - 3 x 3 cm, medium heat when red - don't develop much wall thickness until then.
Hungarian Waxpod - 15 x 3cm, when green are mild, medium when whitish, medium and sweet when red.
I've had some problems with zero germination of my own seeds of HW but only after 3 or 4 generations.
I can recommend Black Hungarian, especially for its wonderful ornamental qualities - it's a bit hotter than HW but is early and reliable. I had trouble with it hybridising last year but that might have been the bad weather (my climbing french beans only hybridise in really bad years).
I got great results with Poblano in 2006 but I got almost nothing in the last 3 years. I didn't think 2009 was that bad - some chillis seem to behave entirely differently given a few extra degrees C.
I'm also interested in replacing sweet peppers with something more spicy. I am trying to grow more seed of couple of very promising types which have all the advantages of a sweet pepper (fleshy, sweet, juicy) but with far more flavour than even the best Italian longhorn types.
One was labelled Pimento Tangerine and looks exactly like a tangerine - it had a barely detectable heat.
The other came as an unnamed fruit from Benington Chilli festival, but has proved to have all the qualities of Cherry Bomb except with almost no heat - just that mild spicy taste.
I've nearly given up on Alma Paprika - mine have had very little flavour at all.
Hope you can suggest some others...
Cheers.