Modafinil analogues like Modafiendz are not a bad choice if you dont have a huge tolerance to stims. Very handy for a functional energy boost if you're feeling tired, lacking motivation, not slept well etc. It's not very recreational or euphoric but provides a noticeable if subtle mood lift too.
You can get the Modafeindz analogues from RC sites, but these seem to be twice the price and half the strength of the medicinal 'real' Modafinil, which can be obtained pretty easily from online Pharms. At first when my tolerance was low i found the 200mg pills so powerfull that I'd have to halve them, the effects last 6-8 hours followed by a pretty grim mood and energy crash. Re-dsoing tends not to work well atall, leading to headaches, irritabilty, stress etc. I'm not sure if its because my Modafinil is way past its sell by date or if i have developed a huge tolerance to stims in general, but currently i dont feel anything at all even from 2 x 200 mg pills.

I'll re-order and find out whether its the pills that are fucked or if it's me. 8(
There's also meant to be a new MPA analogue; Thiopropamine on sale at selected RC vendors. Every time I've checked though it's never been in stock.

Many people did not rate MPA itself, let alone MPA analogues. If it does become available before the ban and if its anyway any good I'll probably get some in, as there's very little choice on the UK market at this stage of the RC game.
Btw avoid Mexedrone at all costs. It is absolute bunk shite. The only 'stimulant' that has ever made me feel so sleepy that I went to bed early, and that was after hoofing a whole gram within an hour or 2.
You could also consider Kratom, many strains are very stimulating if you have no tolerance. Beware though that it acts on opiate receptors amongst many others, and can easily become physicaly addictive if taken every day for week after week.